treatments-xml/data/03/F3/AE/03F3AE42FF86FFEDFEA00755FA4F3081.xml

<document ID-DOI="10.1093/zoolinnean/zlac019" ID-ISSN="0024-4082" ID-Zenodo-Dep="7381112" approvalRequired="1" checkinTime="1669807628251" checkinUser="plazi" docAuthor="Corrie, Joshua E &amp; Fordyce, R Ewan" docDate="2022" docId="03F3AE42FF86FFEDFEA00755FA4F3081" docLanguage="en" docName="zlac019.pdf" docOrigin="Zoological Journal of the Linnean Society 196 (4)" docSource="https://academic.oup.com/zoolinnean/article/196/4/1637/6598844" docStyle="DocumentStyle:36B3BD6A90C22AB4F7F465C853188CC8.7:ZoolJLinnSoc.2017-.journal_article" docStyleId="36B3BD6A90C22AB4F7F465C853188CC8" docStyleName="ZoolJLinnSoc.2017-.journal_article" docStyleVersion="7" docTitle="Kekenodon onamata , Hector 1881" docType="treatment" docVersion="1" lastPageNumber="1656" masterDocId="FFCAD63AFF85FFFEFFA00408FFDF361A" masterDocTitle="A redescription and re-evaluation of Kekenodon onamata (Mammalia: Cetacea), a late-surviving archaeocete from the Late Oligocene of New Zealand" masterLastPageNumber="1670" masterPageNumber="1637" pageNumber="1640" updateTime="1669905974674" updateUser="diego">
<mods:mods xmlns:mods="http://www.loc.gov/mods/v3">
<mods:titleInfo>
<mods:title>A redescription and re-evaluation of Kekenodon onamata (Mammalia: Cetacea), a late-surviving archaeocete from the Late Oligocene of New Zealand</mods:title>
</mods:titleInfo>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Corrie, Joshua E</mods:namePart>
</mods:name>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Fordyce, R Ewan</mods:namePart>
</mods:name>
<mods:typeOfResource>text</mods:typeOfResource>
<mods:relatedItem type="host">
<mods:titleInfo>
<mods:title>Zoological Journal of the Linnean Society</mods:title>
</mods:titleInfo>
<mods:part>
<mods:date>2022</mods:date>
<mods:detail type="pubDate">
<mods:number>2022-12-01</mods:number>
</mods:detail>
<mods:detail type="volume">
<mods:number>196</mods:number>
</mods:detail>
<mods:detail type="issue">
<mods:number>4</mods:number>
</mods:detail>
<mods:extent unit="page">
<mods:start>1637</mods:start>
<mods:end>1670</mods:end>
</mods:extent>
</mods:part>
</mods:relatedItem>
<mods:location>
<mods:url>https://academic.oup.com/zoolinnean/article/196/4/1637/6598844</mods:url>
</mods:location>
<mods:classification>journal article</mods:classification>
<mods:identifier type="DOI">10.1093/zoolinnean/zlac019</mods:identifier>
<mods:identifier type="ISSN">0024-4082</mods:identifier>
<mods:identifier type="Zenodo-Dep">7381112</mods:identifier>
</mods:mods>
<treatment LSID="urn:lsid:plazi:treatment:03F3AE42FF86FFEDFEA00755FA4F3081" httpUri="http://treatment.plazi.org/id/03F3AE42FF86FFEDFEA00755FA4F3081" lastPageId="19" lastPageNumber="1656" pageId="3" pageNumber="1640">
<subSubSection box="[256,685,861,886]" pageId="3" pageNumber="1640" type="nomenclature">
<paragraph blockId="3.[256,685,861,886]" box="[256,685,861,886]" pageId="3" pageNumber="1640">
<heading box="[256,685,861,886]" centered="true" fontSize="9" level="2" pageId="3" pageNumber="1640" reason="2">
<taxonomicName authority="HECTOR, 1881" authorityName=", Hector" authorityYear="1881" box="[256,685,861,886]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[256,514,861,884]" italics="true" pageId="3" pageNumber="1640">KEKENODON ONAMATA</emphasis>
<bibRefCitation author="Hector J" box="[521,685,861,886]" pageId="3" pageNumber="1640" pagination="434 - 436" refId="ref24521" refString="Hector J. 1881. Notes on New Zealand Cetacea, recent and fossil. Transactions of the New Zealand Institute 13: 434 - 436." type="journal article" year="1881">HECTOR, 1881</bibRefCitation>
</taxonomicName>
</heading>
</paragraph>
</subSubSection>
<subSubSection pageId="3" pageNumber="1640" type="etymology">
<paragraph blockId="3.[163,778,933,986]" pageId="3" pageNumber="1640">
<emphasis box="[163,425,933,955]" italics="true" pageId="3" pageNumber="1640">Etymology: Onamata</emphasis>
means ‘of long ago’ in Te Reo Māori.
</paragraph>
</subSubSection>
<subSubSection lastPageId="4" lastPageNumber="1641" pageId="3" pageNumber="1640" type="diagnosis">
<paragraph blockId="3.[163,779,1026,1907]" pageId="3" pageNumber="1640">
<emphasis box="[163,778,1026,1048]" italics="true" pageId="3" pageNumber="1640">
Emended diagnosis of species: 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[539,778,1026,1048]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">Kekenodon onamata</taxonomicName>
</emphasis>
is a large-sized (
<quantity box="[385,465,1057,1079]" metricMagnitude="0" metricUnit="m" metricValue="8.5" metricValueMax="9.0" metricValueMin="8.0" pageId="3" pageNumber="1640" unit="m" value="8.5" valueMax="9.0" valueMin="8.0">8–9 m</quantity>
estimated body length) heterodont archaeocete that differs from archaeocetes basal to the 
<taxonomicName box="[356,565,1118,1140]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
(
<taxonomicName box="[594,769,1118,1140]" class="Mammalia" family="Protocetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Protocetidae</taxonomicName>
, 
<taxonomicName authorityName="Kumar &amp; Sahni" authorityYear="1986" box="[163,389,1149,1171]" class="Mammalia" family="Remingtonocetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Remingtonocetidae</taxonomicName>
, 
<taxonomicName box="[400,574,1149,1171]" class="Mammalia" family="Ambulocetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Ambulocetidae</taxonomicName>
and 
<taxonomicName box="[634,771,1149,1171]" class="Mammalia" family="Pakicetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Pakicetidae</taxonomicName>
) in possessing a prominent lateral tuberosity located lateral to the mallear fossa and posterior cheek teeth with multiple accessory denticles. 
<taxonomicName authorityName=", Hector" authorityYear="1881" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">
<emphasis italics="true" pageId="3" pageNumber="1640">Kekenodon onamata</emphasis>
</taxonomicName>
differs from 
<taxonomicName box="[429,609,1272,1294]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
in possessing a subrectangular supraorbital process of the frontal that is transversely wider than anteroposteriorly long, diminutive foramina on the dorsal surface of the frontal, prominent lateral tuberosity, mallear fossa positioned more medial to the lateral tuberosity, a medial edge of the anterior process of the periotic and anterior edge of the pars cochlearis forming an obtuse angle, rounded anteromedial angle of the pars cochlearis, pars cochlearis with a hemispherical ventral profile, reduced superior process of the periotic forming a low-lying ridge with distinct anterior and posterior apices, gently concave suprameatal fossa, and lower molariform teeth with accessory denticles on the anterior surface of the crown in place of an re-entrant groove. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[387,629,1732,1753]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[387,629,1732,1753]" italics="true" pageId="3" pageNumber="1640">Kekenodon onamata</emphasis>
</taxonomicName>
differs from other Pelagiceti in possessing a protocone remnant in permanent posterior cheek teeth and upper-posterior cheek teeth with a third lingual root.
</paragraph>
<paragraph blockId="3.[163,779,1026,1907]" lastBlockId="3.[827,1443,197,1905]" pageId="3" pageNumber="1640">
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[187,449,1854,1876]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[187,449,1854,1876]" italics="true" pageId="3" pageNumber="1640">Kekenodon onamata</emphasis>
</taxonomicName>
retains archaic features differing from Neoceti including: dorsal and ventral vestibular areas of the internal acoustic meatus separated by an indistinct transverse crest and triplerooted cheek teeth.
</paragraph>
<paragraph blockId="3.[827,1443,197,1905]" pageId="3" pageNumber="1640">
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[851,1104,289,311]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[851,1104,289,311]" italics="true" pageId="3" pageNumber="1640">Kekenodon onamata</emphasis>
</taxonomicName>
differs from Odontoceti in lacking evidence of skull telescoping indicative of echolocation including the posterior and posterolateral expansion and inflation of the maxilla and premaxilla dorsally covering the frontal, and in possessing large and strongly heterodont teeth with postcanines having numerous large and triangular accessory denticles on the anterior and posterior margins of the crown (excluding 
<taxonomicName box="[951,1128,535,556]" class="Mammalia" family="Inticetidae" genus="Inticetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="vertizi">
<emphasis box="[951,1128,535,556]" italics="true" pageId="3" pageNumber="1640">Inticetus vertizi</emphasis>
</taxonomicName>
and 
<taxonomicName authorityName="Brandt" authorityYear="1873" box="[1185,1366,534,556]" class="Mammalia" family="Squalodontidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Squalodontidae</taxonomicName>
).
</paragraph>
<paragraph blockId="3.[827,1443,197,1905]" pageId="3" pageNumber="1640">
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[851,1086,565,587]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[851,1086,565,587]" italics="true" pageId="3" pageNumber="1640">Kekenodon onamata</emphasis>
</taxonomicName>
differs from the taxonomically ambiguous 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[978,1255,596,617]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[978,1255,596,617]" italics="true" pageId="3" pageNumber="1640">Phococetus vasconum</emphasis>
</taxonomicName>
in possessing comparatively larger permanent molariform teeth, crowns of denticulate molariform teeth have a symmetrical profile with a less inclined anterior margin and a more distinct sulcus corresponding to the isthmus joining the anterior and posterior roots.
</paragraph>
<paragraph blockId="3.[827,1443,197,1905]" lastBlockId="4.[145,761,197,1875]" lastPageId="4" lastPageNumber="1641" pageId="3" pageNumber="1640">
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[851,1110,780,801]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[851,1110,780,801]" italics="true" pageId="3" pageNumber="1640">Kekenodon onamata</emphasis>
</taxonomicName>
differs from Mysticeti in possessing a pars cochlearis with a longitudinal ventral ridge; from toothed Mysticeti in possessing a larger total body length [excluding 
<taxonomicName box="[1174,1385,872,894]" class="Mammalia" family="Aetiocetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="subFamily" subFamily="Morawanocetinae">Morawanocetinae</taxonomicName>
gen. et. sp. indet. (AMP 9)], a transverse frontomaxillary suture (excluding 
<taxonomicName authority="Barnes et al., 1995" authorityName="Barnes" authorityYear="1995" class="Mammalia" family="Aetiocetidae" genus="Aetiocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="polydentatus">
<emphasis box="[1055,1346,933,954]" italics="true" pageId="3" pageNumber="1640">Aetiocetus polydentatus</emphasis>
<bibRefCitation author="Barnes LG &amp; Kimura M &amp; Furusawa H &amp; Sawamura H" pageId="3" pageNumber="1640" pagination="392 - 431" refId="ref22258" refString="Barnes LG, Kimura M, Furusawa H, Sawamura H. 1995. Classification and distribution of Oligocene Aetiocetidae (Mammalia; Cetacea; Mysticeti) from western North America and Japan. The Island Arc 3: 392 - 431." type="journal article" year="1995">
Barnes 
<emphasis box="[827,887,964,985]" italics="true" pageId="3" pageNumber="1640">et al.</emphasis>
, 1995
</bibRefCitation>
</taxonomicName>
), ascending process of maxilla does not extend posterior to the anterior margin of the frontal, an indistinct superior process that forms a low-lying ridge terminating at anterior and posterior apices (excluding 
<taxonomicName authority="Marx, Tsai &amp; Fordyce, 2015" authorityName="Marx, Tsai &amp; Fordyce" authorityYear="2015" box="[954,1435,1086,1108]" class="Mammalia" family="Aetiocetidae" genus="Fucaia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="buelli">
<emphasis box="[954,1107,1086,1108]" italics="true" pageId="3" pageNumber="1640">Fucaia buelli</emphasis>
<bibRefCitation author="Marx FG &amp; Tsai CH &amp; Fordyce RE" box="[1115,1435,1086,1108]" pageId="3" pageNumber="1640" pagination="150476" refId="ref25732" refString="Marx FG, Tsai CH, Fordyce RE. 2015. A new Early Oligocene toothed ' baleen' whale (Mysticeti: Aetiocetidae) from western North America: one of the oldest and the smallest. Royal Society Open Science 2: 150476." type="journal article" year="2015">Marx, Tsai &amp; Fordyce, 2015</bibRefCitation>
</taxonomicName>
) and some upper postcanines that are triple-rooted; from the previously recognized toothed mysticetes 
<taxonomicName authority="Mitchell, 1989" authorityName="Mitchell" authorityYear="1989" box="[827,1292,1178,1200]" class="Mammalia" family="Llanocetidae" genus="Llanocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="denticrenatus">
<emphasis box="[827,1118,1178,1199]" italics="true" pageId="3" pageNumber="1640">Llanocetus denticrenatus</emphasis>
<bibRefCitation author="Mitchell ED" box="[1125,1292,1178,1200]" pageId="3" pageNumber="1640" pagination="2219 - 2235" refId="ref25867" refString="Mitchell ED. 1989. A new cetacean from the Late Eocene La Meseta Formation, Seymour Island, Antarctic Peninsula. Canadian Journal of Fisheries and Aquatic Sciences 46: 2219 - 2235." type="journal article" year="1989">Mitchell, 1989</bibRefCitation>
</taxonomicName>
, 
<taxonomicName authority="Lambert et al., 2017" authorityName="Lambert" authorityYear="2017" class="Mammalia" family="Mystacodontidae" genus="Mystacodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="selenesis">
<emphasis italics="true" pageId="3" pageNumber="1640">Mystacodon selenesis</emphasis>
<bibRefCitation author="Lambert O &amp; Martinez-Caceres M &amp; Bianucci G &amp; Di Celma C &amp; Salas-Gismondi R &amp; Steurbaut E &amp; Urbina M &amp; de Muizon C" box="[933,1168,1209,1231]" pageId="3" pageNumber="1640" pagination="1535 - 1541" refId="ref25109" refString="Lambert O, Martinez-Caceres M, Bianucci G, Di Celma C, Salas-Gismondi R, Steurbaut E, Urbina M, de Muizon C. 2017. Earliest mysticete from the late Eocene of Peru sheds new light on the origin of baleen whales. Current Biology 27: 1535 - 1541. e 2." type="journal article" year="2017">
Lambert 
<emphasis box="[1041,1098,1209,1230]" italics="true" pageId="3" pageNumber="1640">et al.</emphasis>
, 2017
</bibRefCitation>
</taxonomicName>
and 
<taxonomicName box="[1226,1443,1209,1231]" class="Mammalia" family="Mammalodontidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Mammalodontidae</taxonomicName>
in possessing prominent enamel ornament on both the labial and lingual surfaces of the crown; from 
<taxonomicName authorityName="Mitchell" authorityYear="1989" box="[827,1139,1301,1322]" class="Mammalia" family="Llanocetidae" genus="Llanocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="denticrenatus">
<emphasis box="[827,1139,1301,1322]" italics="true" pageId="3" pageNumber="1640">Llanocetus denticrenatus</emphasis>
</taxonomicName>
in possessing accessory denticles on postcanine teeth that are more closely spaced with a profile that is more triangular and less palmate; from 
<taxonomicName authority="Pritchard, 1939" authorityName="Pritchard" authorityYear="1939" box="[996,1442,1393,1415]" class="Mammalia" family="Squalodontidae" genus="Mammalodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="colliveri">
<emphasis box="[996,1255,1393,1414]" italics="true" pageId="3" pageNumber="1640">Mammalodon colliveri</emphasis>
Pritchard, 
<quantity box="[1387,1442,1393,1414]" metricMagnitude="1" metricUnit="m" metricValue="4.92506" pageId="3" pageNumber="1640" unit="in" value="1939.0">1939</quantity>
</taxonomicName>
in possessing apertures for cochlear aqueduct and fenestra rotunda that are not widely separated; from 
<taxonomicName authority="Fitzgerald, 2006" authorityName="Fitzgerald" authorityYear="2006" box="[827,1265,1485,1507]" class="Mammalia" family="Mammalodontidae" genus="Janjucetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="hunderi">
<emphasis box="[827,1059,1485,1506]" italics="true" pageId="3" pageNumber="1640">Janjucetus hunderi</emphasis>
<bibRefCitation author="Fitzgerald EMG" box="[1068,1265,1485,1507]" pageId="3" pageNumber="1640" pagination="2955 - 2963" refId="ref23347" refString="Fitzgerald EMG. 2006. A bizarre new toothed mysticete (Cetacea) from Australia and the early evolution of baleen whales. Proceedings of the Royal Society B: Biological Sciences 273: 2955 - 2963." type="journal article" year="2006">Fitzgerald, 2006</bibRefCitation>
</taxonomicName>
and 
<taxonomicName authorityName="Marx, Tsai &amp; Fordyce" authorityYear="2015" box="[1328,1410,1485,1506]" class="Mammalia" family="Aetiocetidae" genus="Fucaia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="genus">
<emphasis box="[1328,1410,1485,1506]" italics="true" pageId="3" pageNumber="1640">Fucaia</emphasis>
</taxonomicName>
in lacking an elongate lateral tuberosity that articulates dorsally with the squamosal; from 
<taxonomicName authorityName="Emlong" authorityYear="1966" box="[1258,1408,1546,1568]" class="Mammalia" family="Aetiocetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="family">Aetiocetidae</taxonomicName>
in possessing upper and lower double-rooted posterior cheek teeth with roots joined by a transversely narrow isthmus below the crown base, a transversely broader anterior process of the periotic, dorsoventrally straight anterior keel of the anterior process in the periotic and an ovoid pars cochlearis in medial view; from 
<taxonomicName authority="Emlong, 1966" authorityName="Emlong" authorityYear="1966" class="Mammalia" family="Aetiocetidae" genus="Aetiocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="genus">
<emphasis box="[1329,1443,1730,1751]" italics="true" pageId="3" pageNumber="1640">Aetiocetus</emphasis>
<bibRefCitation author="Emlong D" box="[827,995,1761,1783]" pageId="3" pageNumber="1640" pagination="1 - 51" refId="ref23130" refString="Emlong D. 1966. A new archaic cetacean from the Oligocene of Northwest Oregon. Bulletin of the Museum of Natural History, University of Oregon 3: 1 - 51." type="journal article" year="1966">
Emlong, 
<quantity box="[937,995,1761,1783]" metricMagnitude="1" metricUnit="m" metricValue="4.99364" pageId="3" pageNumber="1640" unit="in" value="1966.0">1966</quantity>
</bibRefCitation>
</taxonomicName>
in possessing distinctly heterodont teeth and double-rooted postcanine teeth; from the previously recognized toothed mysticete 
<taxonomicName authority="Geisler et al., 2017" authorityName="Geisler" authorityYear="2017" class="Mammalia" genus="Coronodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="3" pageNumber="1640" phylum="Chordata" rank="species" species="havensteini">
<emphasis italics="true" pageId="3" pageNumber="1640">Coronodon havensteini</emphasis>
<bibRefCitation author="Geisler JH &amp; Boessenecker RW &amp; Brown M &amp; Beatty BL" box="[984,1233,1853,1875]" pageId="3" pageNumber="1640" pagination="20361 - 2042" refId="ref24197" refString="Geisler JH, Boessenecker RW, Brown M, Beatty BL. 2017. The origin of filter feeding in whales. Current Biology 27: 20361 - 2042. e 2." type="journal article" year="2017">
Geisler 
<emphasis box="[1088,1154,1853,1874]" italics="true" pageId="3" pageNumber="1640">et al.</emphasis>
, 
<quantity box="[1174,1233,1853,1874]" metricMagnitude="1" metricUnit="m" metricValue="5.12318" pageId="3" pageNumber="1640" unit="in" value="2017.0">2017</quantity>
</bibRefCitation>
</taxonomicName>
in possessing a rounded anteromedial corner of the pars cochlearis, postcanine teeth with a more inclined anterior margin of the crown and a primary denticle that is larger than the accessory denticles; from 
<taxonomicName class="Mammalia" family="Mystacodontidae" genus="Mystacodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="selenesis">
<emphasis italics="true" pageId="4" pageNumber="1641">Mystacodon selenesis</emphasis>
</taxonomicName>
in having nasals with a posterior margin positioned further anteriorly; from Chaeomysticeti in possessing an orbitotemporal crest located on the posterior edge of the frontal and functional permanent teeth (possibly excluding the eomysticetid 
<taxonomicName authority="Boessenecker &amp; Fordyce, 2015" authorityName="Boessenecker &amp; Fordyce" authorityYear="2015" class="Mammalia" family="Eomysticetidae" genus="Waharoa" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="ruwhenua">
<emphasis italics="true" pageId="4" pageNumber="1641">Waharoa ruwhenua</emphasis>
Boessenecker &amp; Fordyce, 2015
</taxonomicName>
); from 
<taxonomicName authority="(Barnes et al., 1995)" baseAuthorityName="Barnes" baseAuthorityYear="1995" class="Mammalia" family="Aetiocetidae" genus="Fucaia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="goedertorum">
<emphasis italics="true" pageId="4" pageNumber="1641">Fucaia goedertorum</emphasis>
(
<bibRefCitation author="Barnes LG &amp; Kimura M &amp; Furusawa H &amp; Sawamura H" box="[304,518,473,495]" pageId="4" pageNumber="1641" pagination="392 - 431" refId="ref22258" refString="Barnes LG, Kimura M, Furusawa H, Sawamura H. 1995. Classification and distribution of Oligocene Aetiocetidae (Mammalia; Cetacea; Mysticeti) from western North America and Japan. The Island Arc 3: 392 - 431." type="journal article" year="1995">
Barnes 
<emphasis box="[393,449,473,495]" italics="true" pageId="4" pageNumber="1641">et al.</emphasis>
, 1995
</bibRefCitation>
)
</taxonomicName>
and Chaeomysticeti in possessing an anterior process of the periotic with apex dorsal to the ventral edge of the pars cochlearis; from crown Mysticeti in possessing a straight posterior border of frontal, multiple minute foramina on dorsal surface of the frontals, anterior process of the periotic intermediate in length relative to the pars cochlearis, distinct mallear fossa, distinct fovea epitubaria to accommodate the accessory ossicle of the tympanic bulla, periotic lacking a ventrolateral ridge, ovoid proximal opening of facial canal, relatively wide tympanic bulla, distinct medial and lateral lobes of the tympanic bulla open elliptical foramen of the tympanic bulla, tympanic cavity anteroposteriorly divided by transverse ridge and involucral ridge that is nearly straight; from crown Mysticeti and 
<taxonomicName authorityName="Pritchard" authorityYear="1939" box="[588,726,933,955]" class="Mammalia" family="Squalodontidae" genus="Mammalodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="colliveri">
<emphasis box="[588,611,934,955]" italics="true" pageId="4" pageNumber="1641">M</emphasis>
. 
<emphasis box="[628,726,933,954]" italics="true" pageId="4" pageNumber="1641">colliveri</emphasis>
</taxonomicName>
in lacking a pars cochlearis elongated towards the cranial cavity, tubular fundus of the internal acoustic meatus and protruding lateral wall of internal acoustic meatus from the suprameatal fossa; and from crown Mysticeti and 
<taxonomicName authorityName="Fitzgerald" authorityYear="2006" box="[197,320,1086,1108]" class="Mammalia" family="Mammalodontidae" genus="Janjucetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="hunderi">
<emphasis box="[197,212,1087,1108]" italics="true" pageId="4" pageNumber="1641">J</emphasis>
. 
<emphasis box="[227,320,1086,1107]" italics="true" pageId="4" pageNumber="1641">hunderi</emphasis>
</taxonomicName>
in lacking a fenestra rotunda with a fissure oriented towards the perilymphatic foramen and a caudal tympanic process of the periotic with narrow separation from the facial crest of the periotic with a clear separation between the stapedial muscle fossa and facial sulcus.
</paragraph>
<paragraph blockId="4.[145,761,197,1875]" lastBlockId="4.[809,1425,197,525]" pageId="4" pageNumber="1641">
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[169,424,1270,1292]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[169,424,1270,1292]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName box="[597,755,1270,1292]" class="Mammalia" family="Protocetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="family">Protocetidae</taxonomicName>
, 
<taxonomicName box="[145,385,1301,1323]" class="Mammalia" family="Mammalodontidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="family">Mammalodontidae</taxonomicName>
and 
<taxonomicName box="[460,761,1301,1322]" class="Mammalia" genus="Coronodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="havensteini">
<emphasis box="[460,761,1301,1322]" italics="true" pageId="4" pageNumber="1641">Coronodon havensteini</emphasis>
</taxonomicName>
some upper cheek teeth that are triple-rooted with a third lingual root. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[369,611,1362,1384]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[369,611,1362,1384]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName box="[145,320,1393,1415]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
heterodont teeth composed of singlerooted and single-cusped conical crowns and doublerooted cheek with transversely compressed and tall triangular crowns with accessory denticles. 
<taxonomicName authorityName=", Hector" authorityYear="1881" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName authorityName="Mitchell" authorityYear="1989" box="[422,736,1516,1537]" class="Mammalia" family="Llanocetidae" genus="Llanocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="denticrenatus">
<emphasis box="[422,736,1516,1537]" italics="true" pageId="4" pageNumber="1641">Llanocetus denticrenatus</emphasis>
</taxonomicName>
a large total body length. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[433,674,1546,1568]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[433,674,1546,1568]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName box="[205,473,1577,1598]" class="Mammalia" genus="Coronodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="havensteini">
<emphasis box="[205,473,1577,1598]" italics="true" pageId="4" pageNumber="1641">Coronodon havensteini</emphasis>
</taxonomicName>
a pars cochlearis with a longitudinal ventral ridge and an indistinct superior process that forms a low-lying ridge terminating at anterior and posterior apices. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[516,760,1669,1691]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[516,760,1669,1691]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName box="[290,508,1700,1722]" class="Mammalia" family="Mammalodontidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="family">Mammalodontidae</taxonomicName>
and some Odontoceti (including 
<taxonomicName box="[266,442,1731,1752]" class="Mammalia" family="Inticetidae" genus="Inticetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="vertizi">
<emphasis box="[266,442,1731,1752]" italics="true" pageId="4" pageNumber="1641">Inticetus vertizi</emphasis>
</taxonomicName>
) a median furrow forming a continuous anteroposterior grove on the ventral surface of the tympanic bulla. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[425,672,1791,1813]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[425,672,1791,1813]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName box="[207,428,1822,1844]" class="Mammalia" family="Mammalodontidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="family">Mammalodontidae</taxonomicName>
lower posterior cheek teeth roots joined below the crown base by a transversely narrow isthmus. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[1021,1269,197,219]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[1021,1269,197,219]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName authorityName="Pritchard" authorityYear="1939" box="[809,1064,227,248]" class="Mammalia" family="Squalodontidae" genus="Mammalodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="colliveri">
<emphasis box="[809,1064,227,248]" italics="true" pageId="4" pageNumber="1641">Mammalodon colliveri</emphasis>
</taxonomicName>
and some Odontoceti (including eurhinodelphinids) an involucrum possessing a transverse groove on its dorsal surface, which divides it into a narrower anterior section and wider posterior section. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[1027,1272,350,372]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[1027,1272,350,372]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName authorityName="Sanders &amp; Barnes" authorityYear="2002" box="[809,991,381,403]" class="Mammalia" family="Eomysticetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="family">Eomysticetidae</taxonomicName>
a poorly-developed superior process of the periotic reduced to a low ridge with anterior and posterior apices. 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[1051,1284,442,464]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[1051,1284,442,464]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
shares with 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[809,1051,473,494]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[809,1051,473,494]" italics="true" pageId="4" pageNumber="1641">Phococetus vasconum</emphasis>
</taxonomicName>
longitudinal ridges ornamenting the basal region of the crown of denticulate teeth.
</paragraph>
</subSubSection>
<subSubSection lastPageId="6" lastPageNumber="1643" pageId="4" pageNumber="1641" type="materials_examined">
<paragraph blockId="4.[809,1426,566,925]" pageId="4" pageNumber="1641">
<materialsCitation collectingDate="1880-11-30" collectionCode="NMNZ" country="New Zealand" county="Wharekuri Creek" latitude="-44.666668" location="near the junction of the Wharekuri Creek and Waitaki River in the Waitaki Valley" longLatPrecision="1135" longitude="170.35" municipality="North Otago" pageId="4" pageNumber="1641" specimenCode="NMNZ Ma 306" specimenCount="1" stateProvince="South Island," typeStatus="holotype">
<emphasis box="[809,1117,566,588]" italics="true" pageId="4" pageNumber="1641">
<typeStatus box="[809,912,566,587]" pageId="4" pageNumber="1641">Holotype</typeStatus>
: 
<specimenCode box="[939,1117,566,588]" pageId="4" pageNumber="1641">NMNZ Ma 306</specimenCode>
</emphasis>
, Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand; GNS Science, Avalon, New Zealand, preserves the right supraorbital process of frontal, left periotic and tympanic bulla, 15 isolated teeth and atlas. Collected in 
<date box="[839,1018,719,741]" pageId="4" pageNumber="1641" value="1880-11">
<collectingDate box="[839,1018,719,741]" pageId="4" pageNumber="1641" value="1880-11">November 1880</collectingDate>
</date>
<location LSID="urn:lsid:plazi:treatment:03F3AE42FF86FFEDFEA00755FA4F3081:8E85498FFF81FFFAFBA106D8FA9F351E" country="New Zealand" county="Wharekuri Creek" latitude="-44.666668" longLatPrecision="1135" longitude="170.35" municipality="North Otago" name="near the junction of the Wharekuri Creek and Waitaki River in the Waitaki Valley" pageId="4" pageNumber="1641" stateProvince="South Island,">near the junction of the Wharekuri Creek and Waitaki River in the Waitaki Valley</location>
, 
<collectingMunicipality pageId="4" pageNumber="1641">North Otago</collectingMunicipality>
, 
<collectingRegion box="[890,1044,781,803]" pageId="4" pageNumber="1641">South Island,</collectingRegion>
<collectingCountry box="[1052,1205,781,803]" name="New Zealand" pageId="4" pageNumber="1641">New Zealand</collectingCountry>
, by A. McKay. New Zealand Map Series 260 grid reference I40:010122, GPS coordinates (approximately 
<geoCoordinate box="[1206,1293,842,863]" degrees="44" direction="south" minutes="40" orientation="latitude" pageId="4" pageNumber="1641" precision="925" value="-44.666668">44º40’S</geoCoordinate>
, 
<geoCoordinate box="[1307,1410,842,863]" degrees="170" direction="east" minutes="21" orientation="longitude" pageId="4" pageNumber="1641" precision="925" value="170.35">170º21’E</geoCoordinate>
). Fossil record number I40/f35 (New Zealand fossil record file, Geosciences Society of New Zealand).
</materialsCitation>
</paragraph>
<paragraph blockId="4.[809,1426,966,1877]" lastBlockId="6.[145,762,197,1108]" lastPageId="6" lastPageNumber="1643" pageId="4" pageNumber="1641">
<emphasis box="[809,1305,966,988]" italics="true" pageId="4" pageNumber="1641">
Stratigraphy and age: 
<collectionCode box="[1115,1199,967,988]" country="New Zealand" httpUri="http://grbio.org/cool/fg7h-t7tk" name="Museum of New Zealand Te Papa Tongarewa" pageId="4" pageNumber="1641" type="Museum">NMNZ</collectionCode>
Ma 306
</emphasis>
from the upper Oligocene 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[1004,1194,997,1019]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="genus">
<emphasis box="[1004,1130,997,1018]" italics="true" pageId="4" pageNumber="1641">Kekenodon</emphasis>
Beds
</taxonomicName>
at the approximate junction of the Wharekuri Creek and Waitaki River in the Waitaki Valley, 
<quantity box="[1030,1102,1058,1080]" metricMagnitude="4" metricUnit="m" metricValue="1.1" pageId="4" pageNumber="1641" unit="km" value="11.0">11 km</quantity>
north-west of Kurow, North 
<collectingRegion box="[809,880,1089,1110]" country="New Zealand" name="Otago" pageId="4" pageNumber="1641">Otago</collectingRegion>
, South Island, 
<collectingCountry box="[1056,1209,1089,1111]" name="New Zealand" pageId="4" pageNumber="1641">New Zealand</collectingCountry>
(
<figureCitation box="[1225,1291,1089,1111]" captionStart="Figure 2" captionStartId="5.[163,242,1385,1407]" captionTargetBox="[164,1442,199,1341]" captionTargetId="figure-188@5.[163,1443,195,1345]" captionTargetPageId="5" captionText="Figure 2. Geographic and geologic context of the holotype locality of Kekenodon onamata. A, map of South Island of New Zealand. B, map of the North Otago and Southern Canterbury districts.The star located in the upper left at Wharekuri Creek denotes the approximate type locality of the Kekenodon onamata holotype (NMNZ Ma 306). C, Generalized stratigraphic column of the K. onamata type locality in the Waitaki Valley near the junction of the Wharekuri Creek and Waitaki River, modified from McKay (1882a, b), Marwick (1959), and Fordyce and Watson (1998). Abbreviations: EM, earthquakes’ marl; Ld, Landon series, Duntroonian Stage; Lw, Landon series Waitakian Stage; Lwh, Landon series Whaingaroan Stage." figureDoi="http://doi.org/10.5281/zenodo.7381118" httpUri="https://zenodo.org/record/7381118/files/figure.png" pageId="4" pageNumber="1641">Fig. 2</figureCitation>
). The exact 
<typeStatus box="[809,859,1120,1141]" pageId="4" pageNumber="1641">type</typeStatus>
locality and horizon is now submerged below the Waitaki Hydroelectric Lake. 
<bibRefCitation author="McKay A" box="[1164,1347,1150,1172]" pageId="4" pageNumber="1641" pagination="56 - 92" refId="ref25459" refString="McKay A. 1882 a. Geology of the Waitaki Valley and parts of Vincent and Lake Counties. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 56 - 92." type="journal article" year="1882">McKay (1882a)</bibRefCitation>
noted that the source horizon of 
<emphasis box="[1111,1284,1181,1202]" italics="true" pageId="4" pageNumber="1641">
<collectionCode box="[1111,1191,1181,1202]" country="New Zealand" httpUri="http://grbio.org/cool/fg7h-t7tk" name="Museum of New Zealand Te Papa Tongarewa" pageId="4" pageNumber="1641" type="Museum">NMNZ</collectionCode>
Ma 306
</emphasis>
was located on the lower-middle or lower-third of the outcrop of the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[887,1084,1242,1264]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="genus">
<emphasis box="[887,1016,1242,1263]" italics="true" pageId="4" pageNumber="1641">Kekenodon</emphasis>
Beds
</taxonomicName>
and was vulnerable to high waters during flooding events of the Waitaki River. The 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[863,1060,1303,1325]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="genus">
<emphasis box="[863,992,1303,1324]" italics="true" pageId="4" pageNumber="1641">Kekenodon</emphasis>
Beds
</taxonomicName>
were named by 
<bibRefCitation author="Hector J" box="[1261,1425,1303,1325]" pageId="4" pageNumber="1641" pagination="9 - 32" refId="ref24548" refString="Hector J. 1882. Progress report, 1881. New Zealand Geological Survey Reports of Geological Explorations, 1881 14: 9 - 32." type="journal article" year="1882">Hector (1882)</bibRefCitation>
based on the discovery of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[1100,1331,1334,1356]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[1100,1331,1334,1356]" italics="true" pageId="4" pageNumber="1641">Kekenodon onamata</emphasis>
</taxonomicName>
and are restricted to the Wharekuri area in the Waitaki Valley. The 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[862,1056,1395,1417]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="genus">
<emphasis box="[862,990,1395,1416]" italics="true" pageId="4" pageNumber="1641">Kekenodon</emphasis>
Beds
</taxonomicName>
directly underlie the Otekaike Limestone and unconformably overlie the Wharekuri Greensand at a disconformity (
<bibRefCitation author="McKay A" box="[1162,1321,1457,1478]" pageId="4" pageNumber="1641" pagination="56 - 92" refId="ref25459" refString="McKay A. 1882 a. Geology of the Waitaki Valley and parts of Vincent and Lake Counties. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 56 - 92." type="journal article" year="1882">McKay, 1882a</bibRefCitation>
, b; 
<bibRefCitation author="Gage M" pageId="4" pageNumber="1641" pagination="1 - 135" refId="ref24068" refString="Gage M. 1957. The geology of the Waitaki subdivision. New Zealand Geological Survey Bulletin 55: 1 - 135." type="journal article" year="1957">Gage, 1957</bibRefCitation>
; 
<bibRefCitation author="Marwick J" box="[874,1040,1487,1509]" pageId="4" pageNumber="1641" pagination="173" refId="ref25663" refString="Marwick J. 1959. Kekenodon beds. In: Fleming CA ed. Lexique, Stratigraphique International, Oceania. Fascicule 4. New Zealand. Paris: Centre National de la Recherche Scientifique, 173." type="book chapter" year="1959">Marwick, 1959</bibRefCitation>
; 
<bibRefCitation author="Fordyce RE &amp; Watson AG" box="[1050,1317,1487,1509]" pageId="4" pageNumber="1641" pagination="161 - 176" refId="ref24007" refString="Fordyce RE, Watson AG. 1998. Vertebral pathology in an Early Oligocene whale (Cetacea,? Mysticeti) from Wharekuri, North Otago, New Zealand. In: Grimm KI, Grimm MC, Morlo M, eds. Festschift zum 70 Geburtstag von Karlheinz Rothausen. Mainz: Naturhistoriches Museum Mainz, 161 - 176." type="book chapter" year="1998">Fordyce &amp; Watson, 1998</bibRefCitation>
). 
<bibRefCitation author="Fordyce RE &amp; Watson AG" pageId="4" pageNumber="1641" pagination="161 - 176" refId="ref24007" refString="Fordyce RE, Watson AG. 1998. Vertebral pathology in an Early Oligocene whale (Cetacea,? Mysticeti) from Wharekuri, North Otago, New Zealand. In: Grimm KI, Grimm MC, Morlo M, eds. Festschift zum 70 Geburtstag von Karlheinz Rothausen. Mainz: Naturhistoriches Museum Mainz, 161 - 176." type="book chapter" year="1998">Fordyce &amp; Watson (1998)</bibRefCitation>
observed the disconformity between the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[850,1033,1549,1571]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="genus">
<emphasis box="[850,974,1549,1570]" italics="true" pageId="4" pageNumber="1641">Kekenodon</emphasis>
Beds
</taxonomicName>
and theWharekuri Greensand‘ 
<quantity metricMagnitude="0" metricUnit="m" metricValue="1.5" metricValueMax="2.0" metricValueMin="1.0" pageId="4" pageNumber="1641" unit="m" value="1.5" valueMax="2.0" valueMin="1.0">1–2 m</quantity>
below terrace gravels 
<quantity box="[1089,1160,1579,1601]" metricMagnitude="2" metricUnit="m" metricValue="1.0" pageId="4" pageNumber="1641" unit="m" value="100.0">100 m</quantity>
upstream (south-west) from the old stone bridge across Wharekuri Creek’. The disconformity separates early Whaingaroan Stage [
<taxonomicName authorityName="Hornibrook" authorityYear="1965" box="[895,1352,1671,1692]" class="Globothalamea" family="Globigerinidae" genus="Globigerina" kingdom="Chromista" order="Rotaliida" pageId="4" pageNumber="1641" phylum="Foraminifera" rank="species" species="angiporoides" subGenus="Subbotina">
<emphasis box="[895,1037,1671,1692]" italics="true" pageId="4" pageNumber="1641">Globigerina</emphasis>
(
<emphasis box="[1056,1179,1671,1692]" italics="true" pageId="4" pageNumber="1641">Subbotina</emphasis>
) 
<emphasis box="[1198,1352,1671,1692]" italics="true" pageId="4" pageNumber="1641">angiporoides</emphasis>
</taxonomicName>
zone] from the upper Whaingaroan and Duntroonian Stages (
<taxonomicName authorityName="Jenkins" authorityYear="1960" box="[908,1194,1733,1754]" class="Globothalamea" family="Globigerinidae" genus="Globigerina" kingdom="Chromista" order="Rotaliida" pageId="4" pageNumber="1641" phylum="Foraminifera" rank="species" species="euapertura">
<emphasis box="[908,1194,1733,1754]" italics="true" pageId="4" pageNumber="1641">Globigerina euapertura</emphasis>
</taxonomicName>
zone) (
<bibRefCitation author="Hornibrook N de &amp; Brazier RC &amp; Strong CP" pageId="4" pageNumber="1641" pagination="1 - 175" refId="ref24699" refString="Hornibrook N de B, Brazier RC, Strong CP. 1989. Manual of New Zealand Permian to Pleistocene foraminiferal biostratigraphy. New Zealand Geological Survey Paleontological Bulletin 56: 1 - 175." type="journal article" year="1989">
Hornibrook 
<emphasis box="[809,869,1763,1785]" italics="true" pageId="4" pageNumber="1641">et al.</emphasis>
, 1989
</bibRefCitation>
: Maxwell in 
<bibRefCitation author="Beu AG &amp; Maxwell PA &amp; Brazier RC" box="[1103,1293,1763,1785]" pageId="4" pageNumber="1641" pagination="1 - 518" refId="ref22301" refString="Beu AG, Maxwell PA, Brazier RC. 1990. Cenozoic Mollusca of New Zealand. New Zealand Geological Survey Paleontological Bulletin 58: 1 - 518." type="journal article" year="1990">
Beu 
<emphasis box="[1159,1219,1763,1785]" italics="true" pageId="4" pageNumber="1641">et al.</emphasis>
, 1990
</bibRefCitation>
). Near the Wharekuri Creek in the Waitaki Valley, 
<quantity box="[1273,1346,1794,1816]" metricMagnitude="4" metricUnit="m" metricValue="1.1" pageId="4" pageNumber="1641" unit="km" value="11.0">11 km</quantity>
northwest of Kurow, the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[1020,1206,1825,1847]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="4" pageNumber="1641" phylum="Chordata" rank="genus">
<emphasis box="[1020,1144,1825,1846]" italics="true" pageId="4" pageNumber="1641">Kekenodon</emphasis>
Beds
</taxonomicName>
are a grey to green, fossiliferous, massively to decimetre-bedded (
<quantity box="[1326,1425,1855,1877]" metricMagnitude="1" metricUnit="m" metricValue="4.5" metricValueMax="6.0" metricValueMin="3.0" pageId="4" pageNumber="1641" unit="m" value="45.0" valueMax="60.0" valueMin="30.0">30–60 m</quantity>
thick), calcareous, glauconitic quartz greensand (
<bibRefCitation author="Hector J" box="[171,311,1623,1644]" pageId="5" pageNumber="1642" pagination="434 - 436" refId="ref24521" refString="Hector J. 1881. Notes on New Zealand Cetacea, recent and fossil. Transactions of the New Zealand Institute 13: 434 - 436." type="journal article" year="1881">Hector, 1881</bibRefCitation>
; 
<bibRefCitation author="McKay A" box="[322,478,1623,1644]" pageId="5" pageNumber="1642" pagination="56 - 92" refId="ref25459" refString="McKay A. 1882 a. Geology of the Waitaki Valley and parts of Vincent and Lake Counties. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 56 - 92." type="journal article" year="1882">McKay, 1882a</bibRefCitation>
, b; 
<bibRefCitation author="Marwick J" box="[513,680,1622,1645]" pageId="5" pageNumber="1642" pagination="173" refId="ref25663" refString="Marwick J. 1959. Kekenodon beds. In: Fleming CA ed. Lexique, Stratigraphique International, Oceania. Fascicule 4. New Zealand. Paris: Centre National de la Recherche Scientifique, 173." type="book chapter" year="1959">Marwick, 1959</bibRefCitation>
). 
<bibRefCitation author="McKay A" pageId="5" pageNumber="1642" pagination="56 - 92" refId="ref25459" refString="McKay A. 1882 a. Geology of the Waitaki Valley and parts of Vincent and Lake Counties. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 56 - 92." type="journal article" year="1882">McKay (1882a)</bibRefCitation>
noted a higher fossiliferous content toward the central part of the Wharekuri Basin, along the banks of the Waitaki River, with the highest concentration of fossils occurring in the middle to upper portion of the 
<taxonomicName authority="Beds (McKay, 1882 b)" authorityName="Beds (McKay" authorityYear="1882" box="[210,602,1776,1798]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="5" pageNumber="1642" phylum="Chordata" rank="genus">
<emphasis box="[210,339,1776,1797]" italics="true" pageId="5" pageNumber="1642">Kekenodon</emphasis>
Beds (
<bibRefCitation author="McKay A" box="[424,590,1776,1798]" pageId="5" pageNumber="1642" pagination="98 - 106" refId="ref25493" refString="McKay A. 1882 b. On the younger deposits of the Wharekuri Basin and the lower Waitaki Valley. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 98 - 106." type="journal article" year="1882">McKay, 1882b</bibRefCitation>
)
</taxonomicName>
. 
<bibRefCitation author="Hector J" box="[615,779,1776,1797]" pageId="5" pageNumber="1642" pagination="9 - 32" refId="ref24548" refString="Hector J. 1882. Progress report, 1881. New Zealand Geological Survey Reports of Geological Explorations, 1881 14: 9 - 32." type="journal article" year="1882">Hector (1882)</bibRefCitation>
and 
<bibRefCitation author="McKay A" box="[215,393,1807,1828]" pageId="5" pageNumber="1642" pagination="56 - 92" refId="ref25459" refString="McKay A. 1882 a. Geology of the Waitaki Valley and parts of Vincent and Lake Counties. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 56 - 92." type="journal article" year="1882">McKay (1882a)</bibRefCitation>
previously dated the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="5" pageNumber="1642" phylum="Chordata" rank="genus">
<emphasis box="[652,779,1807,1828]" italics="true" pageId="5" pageNumber="1642">Kekenodon</emphasis>
Beds
</taxonomicName>
at Mid-Eocene and ‘Upper Eocene’, respectively. More recently, foraminifera sampling and abundance of the mollusk 
<taxonomicName authority="(Marwick, 1924)" baseAuthorityName="Marwick" baseAuthorityYear="1924" class="Bivalvia" family="Pectinidae" genus="Serripecten" kingdom="Animalia" order="Pectinida" pageId="5" pageNumber="1642" phylum="Mollusca" rank="species" species="uttleyi" subGenus="Janupecten">
<emphasis box="[1028,1172,1592,1613]" italics="true" pageId="5" pageNumber="1642">Serripecten</emphasis>
(
<emphasis box="[1195,1339,1593,1614]" italics="true" pageId="5" pageNumber="1642">Janupecten</emphasis>
) 
<emphasis box="[1361,1443,1592,1613]" italics="true" pageId="5" pageNumber="1642">uttleyi</emphasis>
(Marwick, 1924)
</taxonomicName>
indicate an Early Oligocene age for the underlying Wharekuri Greensand (
<bibRefCitation author="Marwick J" box="[1269,1437,1653,1675]" pageId="5" pageNumber="1642" pagination="173" refId="ref25663" refString="Marwick J. 1959. Kekenodon beds. In: Fleming CA ed. Lexique, Stratigraphique International, Oceania. Fascicule 4. New Zealand. Paris: Centre National de la Recherche Scientifique, 173." type="book chapter" year="1959">Marwick, 1959</bibRefCitation>
; 
<bibRefCitation author="Hornibrook N de &amp; Brazier RC &amp; Strong CP" box="[827,1097,1684,1706]" pageId="5" pageNumber="1642" pagination="1 - 175" refId="ref24699" refString="Hornibrook N de B, Brazier RC, Strong CP. 1989. Manual of New Zealand Permian to Pleistocene foraminiferal biostratigraphy. New Zealand Geological Survey Paleontological Bulletin 56: 1 - 175." type="journal article" year="1989">
Hornibrook 
<emphasis box="[969,1027,1684,1706]" italics="true" pageId="5" pageNumber="1642">et al.</emphasis>
, 1989
</bibRefCitation>
). The planktonic 
<taxonomicName authorityName="d'Orbigny" authorityYear="1826" box="[1305,1443,1684,1705]" class="Globothalamea" family="Globigerinidae" genus="Globigerina" kingdom="Chromista" order="Rotaliida" pageId="5" pageNumber="1642" phylum="Foraminifera" rank="genus">
<emphasis box="[1305,1443,1684,1705]" italics="true" pageId="5" pageNumber="1642">Globigerina</emphasis>
</taxonomicName>
<taxonomicName authority="Hornibrook, 1965" authorityName="Hornibrook" authorityYear="1965" box="[827,1246,1714,1736]" class="Globothalamea" family="Globigerinidae" genus="Globigerina" kingdom="Chromista" order="Rotaliida" pageId="5" pageNumber="1642" phylum="Foraminifera" rank="species" species="angiporoides" subGenus="Subbotina">
(
<emphasis box="[835,851,1715,1736]" italics="true" pageId="5" pageNumber="1642">S</emphasis>
.) 
<emphasis box="[877,1029,1714,1735]" italics="true" pageId="5" pageNumber="1642">angiporoides</emphasis>
Hornibrook, 1965
</taxonomicName>
and the benthic 
<taxonomicName authority="(Finlay, 1940)" baseAuthorityName="Finlay" baseAuthorityYear="1940" box="[827,1262,1745,1767]" class="Globothalamea" family="Notorotaliidae" genus="Notorotalia" kingdom="Chromista" order="Rotaliida" pageId="5" pageNumber="1642" phylum="Foraminifera" rank="species" species="stachei">
<emphasis box="[827,1073,1745,1766]" italics="true" pageId="5" pageNumber="1642">Notorotalia stachei</emphasis>
(
<bibRefCitation author="Finlay HJ" box="[1095,1253,1745,1767]" pageId="5" pageNumber="1642" pagination="448 - 472" refId="ref23316" refString="Finlay HJ. 1940. New Zealand Foraminifera; key species in stratigraphy-No 4.. In Transactions of the Royal Society of New Zealand 69: 448 - 472." type="journal article" year="1940">Finlay, 1940</bibRefCitation>
)
</taxonomicName>
foraminifera, collected 
<quantity box="[936,980,1776,1797]" metricMagnitude="0" metricUnit="m" metricValue="1.0" pageId="5" pageNumber="1642" unit="m" value="1.0">1 m</quantity>
below the unconformity that separates the Wharekuri Greensand from the overlying 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[827,1016,1837,1859]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="5" pageNumber="1642" phylum="Chordata" rank="genus">
<emphasis box="[827,952,1837,1858]" italics="true" pageId="5" pageNumber="1642">Kekenodon</emphasis>
Beds
</taxonomicName>
, support a lower Whaingaroan Stage (
<bibRefCitation author="Fordyce RE &amp; Watson AG" box="[835,1111,1868,1890]" pageId="5" pageNumber="1642" pagination="161 - 176" refId="ref24007" refString="Fordyce RE, Watson AG. 1998. Vertebral pathology in an Early Oligocene whale (Cetacea,? Mysticeti) from Wharekuri, North Otago, New Zealand. In: Grimm KI, Grimm MC, Morlo M, eds. Festschift zum 70 Geburtstag von Karlheinz Rothausen. Mainz: Naturhistoriches Museum Mainz, 161 - 176." type="book chapter" year="1998">Fordyce &amp; Watson, 1998</bibRefCitation>
). Early interpretations place the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" box="[192,386,197,219]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="genus">
<emphasis box="[192,320,197,218]" italics="true" pageId="6" pageNumber="1643">Kekenodon</emphasis>
Beds
</taxonomicName>
and the Wharekuri Greensand into a single formation (
<bibRefCitation author="Uttley GH" box="[423,562,228,250]" pageId="6" pageNumber="1643" pagination="154 - 168" refId="ref26993" refString="Uttley GH. 1920. Tertiary geology of the area between Wharekuri and the Otiake River, North Otago. Transactions and Proceedings of the New Zealand Institute 52: 154 - 168." type="journal article" year="1920">Uttley, 1920</bibRefCitation>
; 
<bibRefCitation author="Marwick J" box="[576,746,228,250]" pageId="6" pageNumber="1643" pagination="321 - 338" refId="ref25635" refString="Marwick J. 1935. The geology of the Wharekuri Basin, Waitaki Valley. New Zealand Journal of Science and Technology 16: 321 - 338." type="journal article" year="1935">Marwick, 1935</bibRefCitation>
). Similarities in lithology indicate the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="genus">
<emphasis box="[627,761,258,279]" italics="true" pageId="6" pageNumber="1643">Kekenodon</emphasis>
Beds
</taxonomicName>
are instead synonymous with the Kokoamu Greensand, a calcareous greensand characterized by medium to coarse glauconite, scattered macrofossils and phosphatized pebbles (
<bibRefCitation author="Gage M" box="[502,644,381,403]" pageId="6" pageNumber="1643" pagination="1 - 135" refId="ref24068" refString="Gage M. 1957. The geology of the Waitaki subdivision. New Zealand Geological Survey Bulletin 55: 1 - 135." type="journal article" year="1957">Gage, 1957</bibRefCitation>
; 
<bibRefCitation author="Field BD &amp; Browne GH" pageId="6" pageNumber="1643" pagination="1 - 55" refId="ref23284" refString="Field BD, Browne GH. 1986. Lithostratigraphy of Cretaceous and Tertiary rocks, southern Canterbury, New Zealand. New Zealand Geological Survey Record 14: 1 - 55." type="journal article" year="1986">Field &amp; Browne, 1986</bibRefCitation>
; 
<bibRefCitation author="Fordyce RE &amp; Watson AG" box="[311,584,412,434]" pageId="6" pageNumber="1643" pagination="161 - 176" refId="ref24007" refString="Fordyce RE, Watson AG. 1998. Vertebral pathology in an Early Oligocene whale (Cetacea,? Mysticeti) from Wharekuri, North Otago, New Zealand. In: Grimm KI, Grimm MC, Morlo M, eds. Festschift zum 70 Geburtstag von Karlheinz Rothausen. Mainz: Naturhistoriches Museum Mainz, 161 - 176." type="book chapter" year="1998">Fordyce &amp; Watson, 1998</bibRefCitation>
). Lithology and fossil content of the Kokoamu Greensand indicates a middle-shelf environment, with depths between 50 and 
<quantity box="[194,263,504,525]" metricMagnitude="2" metricUnit="m" metricValue="1.0" pageId="6" pageNumber="1643" unit="m" value="100.0">100 m</quantity>
(
<bibRefCitation author="Field BD &amp; Browne GH" box="[277,521,504,526]" pageId="6" pageNumber="1643" pagination="1 - 55" refId="ref23284" refString="Field BD, Browne GH. 1986. Lithostratigraphy of Cretaceous and Tertiary rocks, southern Canterbury, New Zealand. New Zealand Geological Survey Record 14: 1 - 55." type="journal article" year="1986">Field &amp; Browne, 1986</bibRefCitation>
; 
<bibRefCitation author="Ayress MA" box="[532,675,504,525]" pageId="6" pageNumber="1643" pagination="125 - 151" refId="ref22176" refString="Ayress MA. 1993. Ostracod biostratigraphy and paleoecology of the Kokoamu Greensand and Otekaike Limestone (Late Oligocene to Early Miocene), North Otago and South Canterbury, New Zealand. Alcheringa 17: 125 - 151." type="journal article" year="1993">Ayress, 1993</bibRefCitation>
). Fossil assemblages of brachiopods (
<bibRefCitation author="Allan RS" box="[490,626,534,556]" pageId="6" pageNumber="1643" pagination="89 - 92" refId="ref22100" refString="Allan RS. 1938. The Duntroonian Stage: a new division of the Oamaruian system. Appendix. In: Speight R, ed. The geology of Mt Somers district. New Zealand Department of Scientific and Industrial Research Geophysics Memoir 3: 89 - 92." type="journal article" year="1938">Allan, 1938</bibRefCitation>
), ostracods (
<bibRefCitation author="Ayress MA" box="[154,307,565,586]" pageId="6" pageNumber="1643" pagination="125 - 151" refId="ref22176" refString="Ayress MA. 1993. Ostracod biostratigraphy and paleoecology of the Kokoamu Greensand and Otekaike Limestone (Late Oligocene to Early Miocene), North Otago and South Canterbury, New Zealand. Alcheringa 17: 125 - 151." type="journal article" year="1993">Ayress, 1993</bibRefCitation>
) and planktonic (
<bibRefCitation author="Jenkins DG" box="[529,696,565,587]" pageId="6" pageNumber="1643" pagination="1 - 278" refId="ref24814" refString="Jenkins DG. 1971. New Zealand planktonic foraminifera. New Zealand Geological Survey Paleontological Bulletin 42: 1 - 278." type="journal article" year="1971">Jenkins, 1971</bibRefCitation>
) and benthic (
<bibRefCitation author="Hornibrook N de &amp; Brazier RC &amp; Strong CP" box="[244,505,596,618]" pageId="6" pageNumber="1643" pagination="1 - 175" refId="ref24699" refString="Hornibrook N de B, Brazier RC, Strong CP. 1989. Manual of New Zealand Permian to Pleistocene foraminiferal biostratigraphy. New Zealand Geological Survey Paleontological Bulletin 56: 1 - 175." type="journal article" year="1989">
Hornibrook 
<emphasis box="[382,437,596,617]" italics="true" pageId="6" pageNumber="1643">et al.</emphasis>
, 1989
</bibRefCitation>
) foraminifera indicate an upper Whaingaroan Stage (Lower Chattian) for the basal Kokoamu Greensand and the Duntroonian Stage (Upper Chattian) for the upper Kokoamu Greensand (
<bibRefCitation author="Gage M" box="[154,287,718,740]" pageId="6" pageNumber="1643" pagination="1 - 135" refId="ref24068" refString="Gage M. 1957. The geology of the Waitaki subdivision. New Zealand Geological Survey Bulletin 55: 1 - 135." type="journal article" year="1957">Gage, 1957</bibRefCitation>
; 
<bibRefCitation author="Boessenecker RW &amp; Fordyce RE" box="[303,686,718,740]" pageId="6" pageNumber="1643" pagination="107 - 140" refId="ref22372" refString="Boessenecker RW, Fordyce RE. 2015 a. A new eomysticetid (Mammalia: Cetacea) from the Late Oligocene of New Zealand and a re-evaluation of ' Mauicetus' waitakiensis. Papers in Paleontology 1: 107 - 140." type="journal article" year="2015">Boessenecker &amp; Fordyce, 2015a</bibRefCitation>
). 
<bibRefCitation author="Tsai CH &amp; Fordyce RE" pageId="6" pageNumber="1643" pagination="535 - 560" refId="ref26691" refString="Tsai CH, Fordyce RE. 2015. The earliest gulp-feeding mysticete (Cetacea: Mysticeti) From the Oligocene of New Zealand. Journal of Mammalian Evolution 22: 535 - 560." type="journal article" year="2015">Tsai &amp; Fordyce (2015)</bibRefCitation>
noted that the lower boundary of the Duntroonian Stage is delineated by a distinct ‘brachiopod- and pectinid-rich shellbed’ located in the lower to middle Kokoamu Greensand. No record exists to indicate this shellbed was present in the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="genus">
<emphasis box="[637,761,872,893]" italics="true" pageId="6" pageNumber="1643">Kekenodon</emphasis>
Beds
</taxonomicName>
and the current known exposure in Wharekuri Creek is partly obscured by slumping. Following the observations of 
<bibRefCitation author="McKay A" box="[328,504,964,986]" pageId="6" pageNumber="1643" pagination="98 - 106" refId="ref25493" refString="McKay A. 1882 b. On the younger deposits of the Wharekuri Basin and the lower Waitaki Valley. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 98 - 106." type="journal article" year="1882">McKay (1882b)</bibRefCitation>
, the location of the 
<taxonomicName authorityName=", Hector" authorityYear="1881" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[737,755,964,985]" italics="true" pageId="6" pageNumber="1643">K</emphasis>
. 
<emphasis box="[145,245,995,1016]" italics="true" pageId="6" pageNumber="1643">onamata</emphasis>
</taxonomicName>
-bearing horizon in the area of the 
<taxonomicName authority="Beds" authorityName="Beds (McKay" authorityYear="1882" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="genus">
<emphasis box="[637,761,994,1015]" italics="true" pageId="6" pageNumber="1643">Kekenodon</emphasis>
Beds
</taxonomicName>
with the highest concentration of fossils (middle to upper portion) would suggest a Duntroonian age (27.3–25.2 Mya; 
<figureCitation box="[333,396,1086,1108]" captionStart="Figure 2" captionStartId="5.[163,242,1385,1407]" captionTargetBox="[164,1442,199,1341]" captionTargetId="figure-188@5.[163,1443,195,1345]" captionTargetPageId="5" captionText="Figure 2. Geographic and geologic context of the holotype locality of Kekenodon onamata. A, map of South Island of New Zealand. B, map of the North Otago and Southern Canterbury districts.The star located in the upper left at Wharekuri Creek denotes the approximate type locality of the Kekenodon onamata holotype (NMNZ Ma 306). C, Generalized stratigraphic column of the K. onamata type locality in the Waitaki Valley near the junction of the Wharekuri Creek and Waitaki River, modified from McKay (1882a, b), Marwick (1959), and Fordyce and Watson (1998). Abbreviations: EM, earthquakes’ marl; Ld, Landon series, Duntroonian Stage; Lw, Landon series Waitakian Stage; Lwh, Landon series Whaingaroan Stage." figureDoi="http://doi.org/10.5281/zenodo.7381118" httpUri="https://zenodo.org/record/7381118/files/figure.png" pageId="6" pageNumber="1643">Fig. 2</figureCitation>
).
</paragraph>
</subSubSection>
<caption ID-DOI="http://doi.org/10.5281/zenodo.7381118" ID-Zenodo-Dep="7381118" httpUri="https://zenodo.org/record/7381118/files/figure.png" pageId="5" pageNumber="1642" startId="5.[163,242,1385,1407]" targetBox="[164,1442,199,1341]" targetPageId="5">
<paragraph blockId="5.[163,1443,1385,1554]" pageId="5" pageNumber="1642">
<emphasis bold="true" box="[163,268,1385,1407]" pageId="5" pageNumber="1642">Figure 2.</emphasis>
Geographic and geologic context of the holotype locality of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[896,1110,1385,1407]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="5" pageNumber="1642" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[896,1110,1385,1407]" italics="true" pageId="5" pageNumber="1642">Kekenodon onamata</emphasis>
</taxonomicName>
. A, map of South Island of New Zealand. B, map of the North Otago and Southern Canterbury districts. The star located in the upper left at Wharekuri Creek denotes the approximate type locality of the 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[636,850,1444,1466]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="5" pageNumber="1642" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[636,850,1444,1466]" italics="true" pageId="5" pageNumber="1642">Kekenodon onamata</emphasis>
</taxonomicName>
holotype (
<emphasis box="[962,1122,1444,1466]" italics="true" pageId="5" pageNumber="1642">NMNZ Ma 306</emphasis>
). C, Generalized stratigraphic column of the 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[312,433,1473,1495]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="5" pageNumber="1642" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[312,329,1474,1495]" italics="true" pageId="5" pageNumber="1642">K</emphasis>
. 
<emphasis box="[341,433,1474,1495]" italics="true" pageId="5" pageNumber="1642">onamata</emphasis>
</taxonomicName>
type locality in the Waitaki Valley near the junction of the Wharekuri Creek and Waitaki River, modified from 
<bibRefCitation author="McKay A" box="[317,468,1502,1524]" pageId="5" pageNumber="1642" pagination="56 - 92" refId="ref25459" refString="McKay A. 1882 a. Geology of the Waitaki Valley and parts of Vincent and Lake Counties. New Zealand Geological Survey Reports of Geological Explorations 1881 14: 56 - 92." type="journal article" year="1882">McKay (1882a</bibRefCitation>
, b), 
<bibRefCitation author="Marwick J" box="[513,678,1502,1524]" pageId="5" pageNumber="1642" pagination="173" refId="ref25663" refString="Marwick J. 1959. Kekenodon beds. In: Fleming CA ed. Lexique, Stratigraphique International, Oceania. Fascicule 4. New Zealand. Paris: Centre National de la Recherche Scientifique, 173." type="book chapter" year="1959">Marwick (1959)</bibRefCitation>
, and 
<bibRefCitation author="Fordyce RE &amp; Watson AG" box="[737,1022,1502,1524]" pageId="5" pageNumber="1642" pagination="161 - 176" refId="ref24007" refString="Fordyce RE, Watson AG. 1998. Vertebral pathology in an Early Oligocene whale (Cetacea,? Mysticeti) from Wharekuri, North Otago, New Zealand. In: Grimm KI, Grimm MC, Morlo M, eds. Festschift zum 70 Geburtstag von Karlheinz Rothausen. Mainz: Naturhistoriches Museum Mainz, 161 - 176." type="book chapter" year="1998">Fordyce and Watson (1998)</bibRefCitation>
. Abbreviations: EM, earthquakes’ marl; Ld, Landon series, Duntroonian Stage; Lw, Landon series Waitakian Stage; Lwh, Landon series Whaingaroan Stage.
</paragraph>
</caption>
<subSubSection lastPageId="19" lastPageNumber="1656" pageId="6" pageNumber="1643" type="description">
<paragraph blockId="6.[145,430,1165,1189]" box="[145,430,1165,1189]" pageId="6" pageNumber="1643">
<heading box="[145,430,1165,1189]" centered="true" fontSize="9" level="2" pageId="6" pageNumber="1643" reason="2">
<emphasis box="[145,430,1165,1189]" italics="true" pageId="6" pageNumber="1643">Anatomical description</emphasis>
</heading>
</paragraph>
<paragraph blockId="6.[145,762,1205,1902]" lastBlockId="6.[809,1425,197,1783]" pageId="6" pageNumber="1643">
<emphasis box="[145,246,1205,1226]" italics="true" pageId="6" pageNumber="1643">Frontal:</emphasis>
The right supraorbital is preserved in 
<emphasis box="[145,323,1236,1258]" italics="true" pageId="6" pageNumber="1643">
<collectionCode box="[145,226,1237,1258]" country="New Zealand" httpUri="http://grbio.org/cool/fg7h-t7tk" name="Museum of New Zealand Te Papa Tongarewa" pageId="6" pageNumber="1643" type="Museum">NMNZ</collectionCode>
Ma 306
</emphasis>
and is cleanly broken at the median interfrontal suture (
<figureCitation box="[410,483,1266,1288]" captionStart="Figure 3" captionStartId="7.[163,242,1357,1379]" captionTargetBox="[164,1442,199,1312]" captionTargetId="figure-200@7.[163,1446,195,1317]" captionTargetPageId="7" captionText="Figure 3. Right frontal of Kekenodon onamata (NMNZ Ma 306). A, dorsal view. B, ventral view. Specimen whitened with sublimated ammonium chloride." figureDoi="http://doi.org/10.5281/zenodo.7381120" httpUri="https://zenodo.org/record/7381120/files/figure.png" pageId="6" pageNumber="1643">Fig. 3</figureCitation>
; 
<tableCitation box="[501,596,1266,1288]" captionStart="Table 1" captionStartId="7.[162,226,1478,1499]" captionTargetBox="[163,768,1594,1824]" captionTargetPageId="7" captionText="Table 1. Measurements (in mm) of the holotype" pageId="6" pageNumber="1643">Table 1</tableCitation>
). The dorsal profile of the right supraorbital is subrectangular and is transversely wider than anteroposteriorly long (
<quantity box="[209,324,1358,1380]" metricMagnitude="-1" metricUnit="m" metricValue="1.8519999999999999" pageId="6" pageNumber="1643" unit="mm" value="185.2">185.2 mm</quantity>
and 
<quantity box="[382,499,1359,1380]" metricMagnitude="-1" metricUnit="m" metricValue="1.103" pageId="6" pageNumber="1643" unit="mm" value="110.3">110.3 mm</quantity>
, respectively; 
<tableCitation box="[661,746,1358,1380]" captionStart="Table 1" captionStartId="7.[162,226,1478,1499]" captionTargetBox="[163,768,1594,1824]" captionTargetPageId="7" captionText="Table 1. Measurements (in mm) of the holotype" pageId="6" pageNumber="1643">Table 1</tableCitation>
). The supraorbital is dorsoventrally thinnest along the dorsal margin of the orbit. The dorsoventral depth along the preserved medial margin of the supraorbital is greater through the posterior-half than in the anterior-half. Striations at the anteromedial corner of the dorsal surface of the supraorbital represent part of the nasal–frontal suture (medially) and the frontopremaxillary suture (laterally), indicating the nasals and premaxillae overlapped the anterodorsal surface of the frontals. The posterior extension of the striations delineates the posterior termination of the nasals just anterior to the interfrontal suture. The anterior border of the frontal is slightly convex, and its morphology suggests a transversely planar and non-serrate frontomaxillary suture for tight articulation with the maxilla. There is no evidence that an ascending process of maxilla overlapped the dorsal surface of the frontal. The preserved base of the postorbital process of the frontal suggests that the process extended posterolaterally and tapered toward the apex. Several minute foramina are present on the dorsal surface of the frontal. Posteriorly, there is a possible comparatively larger foramen that is oriented toward the postorbital process of the frontal (
<figureCitation box="[910,997,412,434]" captionStart="Figure 3" captionStartId="7.[163,242,1357,1379]" captionTargetBox="[164,1442,199,1312]" captionTargetId="figure-200@7.[163,1446,195,1317]" captionTargetPageId="7" captionText="Figure 3. Right frontal of Kekenodon onamata (NMNZ Ma 306). A, dorsal view. B, ventral view. Specimen whitened with sublimated ammonium chloride." figureDoi="http://doi.org/10.5281/zenodo.7381120" httpUri="https://zenodo.org/record/7381120/files/figure.png" pageId="6" pageNumber="1643">Fig. 3A</figureCitation>
), although this may be an artefact of weathering. The preserved orbit has a length of 
<emphasis box="[809,826,474,495]" italics="true" pageId="6" pageNumber="1643">c.</emphasis>
<quantity box="[833,915,473,495]" metricMagnitude="-2" metricUnit="m" metricValue="6.7" pageId="6" pageNumber="1643" unit="mm" value="67.0">67 mm</quantity>
. In lateral view, the orbit is arched dorsally. The orbitotemporal crest follows the posterodorsal border of the supraorbital from the postorbital process medially toward the parietal. A transversely oriented ridge located anterior to, and running parallel with, the orbitotemporal crest represents the highest point of elevation on the frontals. The posterior ridge extends 
<emphasis box="[908,925,688,709]" italics="true" pageId="6" pageNumber="1643">c.</emphasis>
<quantity box="[933,1028,688,709]" metricMagnitude="-1" metricUnit="m" metricValue="1.08" pageId="6" pageNumber="1643" unit="mm" value="108.0">108 mm</quantity>
mediolaterally across the frontal and may represent an attachment site for anteriorly directed facial muscles or for fascia overlying the m. temporalis. In posterior view, the posterior face of the frontal is concave, forming a fossa probably for the anterior origin of the m. temporalis pars superficialis and m. temporalis pars profunda, agreeing with the interpretation of 
<bibRefCitation author="Carpenter K &amp; White D" box="[1067,1383,902,924]" pageId="6" pageNumber="1643" pagination="1 - 15" refId="ref22737" refString="Carpenter K, White D. 1996. Feeding in the archaeocete whale Zygorhiza kochii (Cetacea: Archaeoceti). Mississippi Geology 7: 1 - 15." type="journal article" year="1996">Carpenter &amp; White (1996)</bibRefCitation>
for 
<taxonomicName baseAuthorityName="Reichenbach" baseAuthorityYear="1847" box="[809,1014,933,954]" class="Mammalia" family="Basilosauridae" genus="Zygorhiza" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="species" species="kochii">
<emphasis box="[809,1014,933,954]" italics="true" pageId="6" pageNumber="1643">Zygorhiza kochii</emphasis>
</taxonomicName>
(Reichenbach in Carus, 1847) in contrast to 
<bibRefCitation author="Uhen MD" box="[940,1082,964,986]" pageId="6" pageNumber="1643" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen (2004)</bibRefCitation>
who argued that the anterior origin of the superficial and deep temporal muscles in 
<taxonomicName authority="Andrews, 1906" authorityName="Andrews" authorityYear="1906" box="[846,1234,1025,1047]" class="Mammalia" family="Basilosauridae" genus="Dorudon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="species" species="atrox">
<emphasis box="[846,1033,1025,1047]" italics="true" pageId="6" pageNumber="1643">Dorudon atrox</emphasis>
<bibRefCitation author="Andrews CW" box="[1044,1234,1025,1047]" pageId="6" pageNumber="1643" refId="ref22149" refString="Andrews CW. 1906. A descriptive catalogue of the tertiary vertebrata of Fayum, Egypt. London: British Museum of Natural History, 324." type="book" year="1906">Andrews, 1906</bibRefCitation>
</taxonomicName>
occurred near the frontoparietal suture and did not extend as far anteriorly as the posterior face of the frontals. Posteromedially, the frontoparietal suture is missing.
</paragraph>
<paragraph blockId="6.[809,1425,197,1783]" pageId="6" pageNumber="1643">
The ventral surface of the preserved frontal has suffered heavy weathering. Previously, 
<bibRefCitation author="Fordyce RE" box="[1257,1425,1178,1200]" pageId="6" pageNumber="1643" refId="ref23467" refString="Fordyce RE. 1978. The morphology and systematics of New Zealand fossil Cetacea. Unpublished D. Phil. Thesis, University of Canterbury." type="book" year="1978">Fordyce (1978)</bibRefCitation>
identified the anteroventral surface of the frontal as being lacrimal, probably due to the appearance of a thin lamella of bone overlapping a second layer. We now interpret this as a laminated pattern representing ossification layers of the frontal. There is no evidence to indicate that the lacrimal articulated with the anterolateral frontal and dorsally overlaid the anterior jugal, forming the anterior wall of the orbit, as seen in basilosaurids (
<bibRefCitation author="Uhen MD" box="[975,1105,1454,1476]" pageId="6" pageNumber="1643" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen, 2004</bibRefCitation>
). Alternatively, the lacrimal may have been anterior to the preorbital process rather than ventrally, similar to 
<taxonomicName authority="(Geisler et al., 2017)" baseAuthorityName="Geisler" baseAuthorityYear="2017" class="Mammalia" genus="Coronodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="6" pageNumber="1643" phylum="Chordata" rank="species" species="havensteini">
<emphasis box="[1139,1425,1515,1536]" italics="true" pageId="6" pageNumber="1643">Coronodon havensteini</emphasis>
(
<bibRefCitation author="Geisler JH &amp; Boessenecker RW &amp; Brown M &amp; Beatty BL" box="[817,1037,1546,1568]" pageId="6" pageNumber="1643" pagination="20361 - 2042" refId="ref24197" refString="Geisler JH, Boessenecker RW, Brown M, Beatty BL. 2017. The origin of filter feeding in whales. Current Biology 27: 20361 - 2042. e 2." type="journal article" year="2017">
Geisler 
<emphasis box="[909,967,1546,1568]" italics="true" pageId="6" pageNumber="1643">et al.</emphasis>
, 2017
</bibRefCitation>
)
</taxonomicName>
. At least four nutrient foramina open on the ventral surface of the frontal. Additionally, the ventral surface of the frontal is highly vascularized. Large sulci are present running mediolaterally to the postorbital process of the frontal. The postorbital ridge has suffered damage but is still slightly noticeable. In the orbital region, the optic infundibulum, along with the orbitosphenoid and presphenoid, are not evident.
</paragraph>
<paragraph blockId="6.[809,1424,1823,1907]" lastBlockId="8.[809,1425,1626,1894]" lastPageId="8" lastPageNumber="1645" pageId="6" pageNumber="1643">
<emphasis box="[809,905,1824,1845]" italics="true" pageId="6" pageNumber="1643">Periotic:</emphasis>
The left periotic is isolated from the skull and is damaged on the dorsal and ventral surfaces (
<figureCitation box="[818,893,1885,1907]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="6" pageNumber="1643">Figs 1</figureCitation>
, 
<figureCitation box="[909,923,1885,1906]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="6" pageNumber="1643">4</figureCitation>
; 
<tableCitation box="[939,1029,1885,1907]" captionStart="Table 2" captionStartId="9.[163,227,196,217]" captionTargetBox="[163,1408,282,635]" captionTargetPageId="9" captionText="Table 2. Measurements (in mm) of the holotype left periotic of Kekenodon onamata (NMNZ Ma 306). Measurements taken to the nearest tenth of a millimetre. Asterisk (*) denotes incomplete measurements as preserved" pageId="6" pageNumber="1643">Table 2</tableCitation>
). The periotic lacks parts of the anterior process and most of the posterior process. Part of the base of the posterior process is preserved, albeit damaged ventrally. Measurements are, therefore, compromised. The preserved length from the anterior margin of the anterior process to the posterior margin of the posterior process is 
<quantity box="[1133,1234,1632,1654]" metricMagnitude="-2" metricUnit="m" metricValue="5.779999999999999" pageId="7" pageNumber="1644" unit="mm" value="57.8">57.8 mm</quantity>
but was probably 
<emphasis box="[827,844,1663,1684]" italics="true" pageId="7" pageNumber="1644">c.</emphasis>
<quantity box="[853,934,1662,1684]" metricMagnitude="-2" metricUnit="m" metricValue="6.5" pageId="7" pageNumber="1644" unit="mm" value="65.0">65 mm</quantity>
when complete. The preserved transverse breadth of the periotic is 
<quantity box="[1135,1242,1693,1715]" metricMagnitude="-2" metricUnit="m" metricValue="2.91" pageId="7" pageNumber="1644" unit="mm" value="29.1">29.1 mm</quantity>
. In ventral view, the anterior process has a teardrop-shaped profile with a blunted anteroventral margin (
<figureCitation box="[1288,1374,1754,1776]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="7" pageNumber="1644">Fig. 4A</figureCitation>
). The anterior process is somewhat long (preserved length = 
<emphasis box="[827,844,1816,1837]" italics="true" pageId="7" pageNumber="1644">c.</emphasis>
<quantity box="[849,948,1816,1838]" metricMagnitude="-2" metricUnit="m" metricValue="2.06" pageId="7" pageNumber="1644" unit="mm" value="20.6">20.6 mm</quantity>
) relative to the length of the pars cochlearis and total preserved length of the periotic (62% and 35%, respectively). Transversely, the anterior process is moderately compressed (width = 
<quantity box="[554,658,1688,1709]" metricMagnitude="-2" metricUnit="m" metricValue="1.7899999999999998" pageId="8" pageNumber="1645" unit="mm" value="17.9">17.9 mm</quantity>
), but not to the extent in eomysticetids and aetiocetids, where marked transverse compression produces a bladelike anterior process. However, the dorsal surface of the anterior process is missing, which may have revealed a blade-like morphology. Multiple vascular canals are exposed from the missing dorsal surface (
<figureCitation box="[817,901,1626,1648]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="8" pageNumber="1645">Fig. 4B</figureCitation>
). Furthermore, the preserved dorsal surface has been polished during previous preparation. The lateral surface of the anterior process is rugose, while the ventrolateral surface is smooth and the medial surface has a smooth-surfaced ventromedial margin with a small section of rugose surface dorsally. The ventral surface of the anterior process is convex, while the medial and lateral surfaces are relatively planar. The anterior keel of the anterior process is
</paragraph>
<caption ID-DOI="http://doi.org/10.5281/zenodo.7381120" ID-Zenodo-Dep="7381120" httpUri="https://zenodo.org/record/7381120/files/figure.png" pageId="7" pageNumber="1644" startId="7.[163,242,1357,1379]" targetBox="[164,1442,199,1312]" targetPageId="7">
<paragraph blockId="7.[163,1443,1357,1408]" pageId="7" pageNumber="1644">
<emphasis bold="true" box="[163,268,1357,1379]" pageId="7" pageNumber="1644">Figure 3.</emphasis>
Right frontal of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[449,663,1357,1379]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="7" pageNumber="1644" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[449,663,1357,1379]" italics="true" pageId="7" pageNumber="1644">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[677,836,1357,1379]" italics="true" pageId="7" pageNumber="1644">NMNZ Ma 306</emphasis>
). A, dorsal view. B, ventral view. Specimen whitened with sublimated ammonium chloride.
</paragraph>
</caption>
<caption pageId="7" pageNumber="1644" startId="7.[162,226,1478,1499]" targetBox="[163,768,1594,1824]" targetIsTable="true" targetPageId="7">
<paragraph blockId="7.[162,760,1478,1559]" pageId="7" pageNumber="1644">
<emphasis bold="true" box="[162,252,1478,1499]" pageId="7" pageNumber="1644">Table 1.</emphasis>
Measurements (in mm) of the holotype right frontal of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[324,536,1507,1529]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="7" pageNumber="1644" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[324,536,1507,1529]" italics="true" pageId="7" pageNumber="1644">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[550,709,1507,1529]" italics="true" pageId="7" pageNumber="1644">
<collectionCode box="[550,623,1508,1529]" country="New Zealand" httpUri="http://grbio.org/cool/fg7h-t7tk" name="Museum of New Zealand Te Papa Tongarewa" pageId="7" pageNumber="1644" type="Museum">NMNZ</collectionCode>
Ma 306
</emphasis>
). Measurements taken to the nearest tenth of a millimetre
</paragraph>
</caption>
<paragraph pageId="7" pageNumber="1644">
<table box="[163,768,1594,1824]" gridcols="2" gridrows="8" pageId="7" pageNumber="1644">
<tr box="[163,768,1594,1616]" gridrow="0" pageId="7" pageNumber="1644">
<th box="[163,662,1594,1616]" gridcol="0" gridrow="0" pageId="7" pageNumber="1644">Anteroposterior length</th>
<th box="[711,768,1594,1616]" gridcol="1" gridrow="0" pageId="7" pageNumber="1644">110.3</th>
</tr>
<tr box="[163,768,1624,1646]" gridrow="1" pageId="7" pageNumber="1644">
<td box="[163,662,1624,1646]" gridcol="0" gridrow="1" pageId="7" pageNumber="1644">Mediolateral transverse width</td>
<td box="[711,768,1624,1646]" gridcol="1" gridrow="1" pageId="7" pageNumber="1644">185.2</td>
</tr>
<tr box="[163,768,1654,1676]" gridrow="2" pageId="7" pageNumber="1644">
<td box="[163,662,1654,1676]" gridcol="0" gridrow="2" pageId="7" pageNumber="1644">Dorsoventral depth along anterior-half of</td>
<td box="[711,768,1654,1676]" gridcol="1" gridrow="2" pageId="7" pageNumber="1644">26.0</td>
</tr>
<tr box="[163,768,1683,1705]" gridrow="3" pageId="7" pageNumber="1644" rowspan-1="1">
<td box="[163,662,1683,1705]" gridcol="0" gridrow="3" pageId="7" pageNumber="1644">preserved medial margin</td>
</tr>
<tr box="[163,768,1713,1735]" gridrow="4" pageId="7" pageNumber="1644">
<td box="[163,662,1713,1735]" gridcol="0" gridrow="4" pageId="7" pageNumber="1644">Dorsoventral depth along posterior-half of</td>
<td box="[711,768,1713,1735]" gridcol="1" gridrow="4" pageId="7" pageNumber="1644">33.2</td>
</tr>
<tr box="[163,768,1743,1765]" gridrow="5" pageId="7" pageNumber="1644" rowspan-1="1">
<td box="[163,662,1743,1765]" gridcol="0" gridrow="5" pageId="7" pageNumber="1644">preserved medial margin</td>
</tr>
<tr box="[163,768,1773,1795]" gridrow="6" pageId="7" pageNumber="1644">
<td box="[163,662,1773,1795]" gridcol="0" gridrow="6" pageId="7" pageNumber="1644">Dorsoventral depth at anteroposterior midpoint</td>
<td box="[711,768,1773,1795]" gridcol="1" gridrow="6" pageId="7" pageNumber="1644">12.8</td>
</tr>
<tr box="[163,768,1802,1824]" gridrow="7" pageId="7" pageNumber="1644" rowspan-1="1">
<td box="[163,662,1802,1824]" gridcol="0" gridrow="7" pageId="7" pageNumber="1644">along dorsal margin of the orbit</td>
</tr>
</table>
</paragraph>
<caption ID-DOI="http://doi.org/10.5281/zenodo.7381122" ID-Zenodo-Dep="7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="8" pageNumber="1645" startId="8.[147,226,1523,1545]" targetBox="[159,1411,199,1481]" targetPageId="8">
<paragraph blockId="8.[145,1424,1523,1575]" pageId="8" pageNumber="1645">
<emphasis bold="true" box="[147,251,1523,1545]" pageId="8" pageNumber="1645">Figure 4.</emphasis>
Left periotic of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[423,637,1524,1546]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="8" pageNumber="1645" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[423,637,1524,1546]" italics="true" pageId="8" pageNumber="1645">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[651,811,1524,1546]" italics="true" pageId="8" pageNumber="1645">NMNZ Ma 306</emphasis>
). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view.
</paragraph>
</caption>
<caption pageId="9" pageNumber="1646" startId="9.[163,227,196,217]" targetBox="[163,1408,282,635]" targetIsTable="true" targetPageId="9">
<paragraph blockId="9.[163,1387,196,247]" pageId="9" pageNumber="1646">
<emphasis bold="true" box="[163,253,196,217]" pageId="9" pageNumber="1646">Table 2.</emphasis>
Measurements (in mm) of the holotype left periotic of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[827,1039,196,218]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="9" pageNumber="1646" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[827,1039,196,218]" italics="true" pageId="9" pageNumber="1646">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[1053,1212,196,218]" italics="true" pageId="9" pageNumber="1646">NMNZ Ma 306</emphasis>
). Measurements taken to the nearest tenth of a millimetre. Asterisk (*) denotes incomplete measurements as preserved
</paragraph>
</caption>
<paragraph pageId="9" pageNumber="1646">
<table box="[163,1408,282,635]" gridcols="2" gridrows="12" pageId="9" pageNumber="1646">
<tr box="[163,1408,282,304]" gridrow="0" pageId="9" pageNumber="1646">
<th box="[163,1314,282,304]" gridcol="0" gridrow="0" pageId="9" pageNumber="1646">Maximum anteroposterior length from preserved anterior apex of anterior process to apex of posterior process</th>
<th box="[1353,1408,282,304]" gridcol="1" gridrow="0" pageId="9" pageNumber="1646">57.8*</th>
</tr>
<tr box="[163,1408,312,334]" gridrow="1" pageId="9" pageNumber="1646">
<td box="[163,1314,312,334]" gridcol="0" gridrow="1" pageId="9" pageNumber="1646">Maximum transverse diameter from medial edge of pars cochlearis to lateral apex of lateral tuberosity</td>
<td box="[1353,1408,312,334]" gridcol="1" gridrow="1" pageId="9" pageNumber="1646">29.9*</td>
</tr>
<tr box="[163,1408,342,364]" gridrow="2" pageId="9" pageNumber="1646">
<td box="[163,1314,342,364]" gridcol="0" gridrow="2" pageId="9" pageNumber="1646">Anteroposterior diameter of anterior process</td>
<td box="[1353,1408,342,364]" gridcol="1" gridrow="2" pageId="9" pageNumber="1646">21.4*</td>
</tr>
<tr box="[163,1408,372,394]" gridrow="3" pageId="9" pageNumber="1646">
<td box="[163,1314,372,394]" gridcol="0" gridrow="3" pageId="9" pageNumber="1646">Transverse diameter of anterior process at midlength of anterior process</td>
<td box="[1353,1408,372,394]" gridcol="1" gridrow="3" pageId="9" pageNumber="1646">21.4*</td>
</tr>
<tr box="[163,1408,403,425]" gridrow="4" pageId="9" pageNumber="1646">
<td box="[163,1314,403,425]" gridcol="0" gridrow="4" pageId="9" pageNumber="1646">Dorsoventral diameter of anterior process at midlength of anterior process</td>
<td box="[1353,1408,403,425]" gridcol="1" gridrow="4" pageId="9" pageNumber="1646">15.3*</td>
</tr>
<tr box="[163,1408,433,455]" gridrow="5" pageId="9" pageNumber="1646">
<td box="[163,1314,433,455]" gridcol="0" gridrow="5" pageId="9" pageNumber="1646">Anteroposterior diameter of pars cochlearis</td>
<td box="[1353,1408,433,455]" gridcol="1" gridrow="5" pageId="9" pageNumber="1646">33.1</td>
</tr>
<tr box="[163,1408,463,485]" gridrow="6" pageId="9" pageNumber="1646">
<td box="[163,1314,463,485]" gridcol="0" gridrow="6" pageId="9" pageNumber="1646">Transverse diameter of pars cochlearis from medial edge of pars cochlearis to lateral margin of fenestra ovalis</td>
<td box="[1353,1408,463,485]" gridcol="1" gridrow="6" pageId="9" pageNumber="1646">17.2</td>
</tr>
<tr box="[163,1408,493,515]" gridrow="7" pageId="9" pageNumber="1646">
<td box="[163,1314,493,515]" gridcol="0" gridrow="7" pageId="9" pageNumber="1646">Maximum dorsoventral diameter of pars cochlearis</td>
<td box="[1353,1408,493,515]" gridcol="1" gridrow="7" pageId="9" pageNumber="1646">20.3</td>
</tr>
<tr box="[163,1408,523,545]" gridrow="8" pageId="9" pageNumber="1646">
<td box="[163,1314,523,545]" gridcol="0" gridrow="8" pageId="9" pageNumber="1646">Distance between aperture for cochlear aqueduct and fenestra rotunda</td>
<td box="[1353,1408,523,545]" gridcol="1" gridrow="8" pageId="9" pageNumber="1646">6.9</td>
</tr>
<tr box="[163,1408,553,575]" gridrow="9" pageId="9" pageNumber="1646">
<td box="[163,1314,553,575]" gridcol="0" gridrow="9" pageId="9" pageNumber="1646">Distance between aperture for vestibular aqueduct and fenestra rotunda</td>
<td box="[1353,1408,553,575]" gridcol="1" gridrow="9" pageId="9" pageNumber="1646">9.9</td>
</tr>
<tr box="[163,1408,583,605]" gridrow="10" pageId="9" pageNumber="1646">
<td box="[163,1314,583,605]" gridcol="0" gridrow="10" pageId="9" pageNumber="1646">Minimum distance between fundus of internal acoustic meatus and aperture for vestibular aqueduct</td>
<td box="[1353,1408,583,605]" gridcol="1" gridrow="10" pageId="9" pageNumber="1646">4.9*</td>
</tr>
<tr box="[163,1408,613,635]" gridrow="11" pageId="9" pageNumber="1646">
<td box="[163,1314,613,635]" gridcol="0" gridrow="11" pageId="9" pageNumber="1646">Minimum distance between fundus of internal acoustic meatus and aperture for cochlear aqueduct</td>
<td box="[1353,1408,613,635]" gridcol="1" gridrow="11" pageId="9" pageNumber="1646">5.6*</td>
</tr>
</table>
</paragraph>
<paragraph blockId="9.[163,780,711,1898]" pageId="9" pageNumber="1646">
shallowly concave in medial and lateral views. The anteroventral angle is moderately triangular with a rounded apex; the anterodorsal angle is not preserved. The posteromedial border of the anterior process is separated from the pars cochlearis by the anterior incisure (
<bibRefCitation author="Mead JG &amp; Fordyce RE" box="[268,520,864,886]" pageId="9" pageNumber="1646" pagination="1 - 248" refId="ref25816" refString="Mead JG, Fordyce RE. 2009. The therian skull: a lexicon with emphasis on the odontocetes. Smithsonian Contributions to Zoology 627: 1 - 248." type="journal article" year="2009">Mead &amp; Fordyce, 2009</bibRefCitation>
). The anterior incisure extends posteroventrally and is bordered laterally by the pars cochlearis and medially by the body of the periotic. An additional groove, possibly vascular, is medially parallel with the anterior incisure.
</paragraph>
<paragraph blockId="9.[163,780,711,1898]" lastBlockId="9.[827,1443,710,1897]" pageId="9" pageNumber="1646">
The anterior process is separated from the body by a prominent groove on the ventral surface that represents the posterodorsal margin of the fovea epitubaria (
<figureCitation captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="9" pageNumber="1646">Fig. 4A</figureCitation>
). The fovea epitubaria accommodates the accessory ossicle of the tympanic bulla (not preserved) and has a triangular profile that forms most of the ventral surface of the anterior process. The posteroventral margin of the fovea epitubaria anteriorly abuts the mallear fossa.The anterior bullar facet is not preserved. A thin lamina of bone separates the fovea epitubaria from the laterally adjacent anteroexternal sulcus. The anteroexternal sulcus extends dorsolaterally from the posteroventral border of the anterior process and runs along the posterolateral face of the anterior process, before terminating at the preserved dorsolateral margin of the anterior process; the anteroexternal sulcus forms most of the posterolateral surface of the anterior process (
<figureCitation box="[367,451,1538,1560]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="9" pageNumber="1646">Fig. 4D</figureCitation>
). The anteroexternal sulcus is similarly rugose as the majority of the lateral surface of the anterior process. The anteroexternal sulcus widens toward the dorsolateral margin of the anterior process. The mallear fossa is posteriorly adjacent to the fovea epitubaria (
<figureCitation box="[539,620,1692,1714]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="9" pageNumber="1646">Fig. 4A</figureCitation>
). The mallear fossa is large (maximum diameter = 
<quantity box="[611,717,1723,1744]" metricMagnitude="-2" metricUnit="m" metricValue="1.08" pageId="9" pageNumber="1646" unit="mm" value="10.8">10.8 mm</quantity>
) and shallow, with a subrounded profile and ventral and slight posteromedial orientation; ridge-like lamellae of bone delineate the margins of the mallear fossa. Minute foramina are present throughout the surface of the mallear fossa, with one relatively larger and more distinct foramen located along the anteromedial margin of the mallear fossa. The fossa incudis is distinct and subrounded and is located posterolateral to the mallear fossa. A small portion of the lateral tuberosity is preserved extending laterally from the lateral margin of the mallear fossa. However, lack of preservation precludes further morphological detail (e.g. if the lateral tuberosity was bulbous or narrow).
</paragraph>
<paragraph blockId="9.[827,1443,710,1897]" pageId="9" pageNumber="1646">
Posteromedial to the mallear fossa, the subrounded distal opening of the facial canal opens posterolaterally into the smooth facial sulcus, which bends posteromedially. The facial sulcus terminates at an indistinct crest that separates the sulcus from the more posteromedial stapedial muscle fossa, which is more deeply excavated with a rugose surface. The ovoid fenestra ovalis is located anterior to the stapedial muscle fossa and medial to the facial sulcus and distal opening of the facial canal, and is separated from each by a low-lying ridge. Originally, the stapes was articulated with the fenestra ovalis, but has since been removed and stored separately [image of articulated stapes in 
<bibRefCitation author="Wilson LE" box="[935,1091,1354,1376]" pageId="9" pageNumber="1646" pagination="1 - 34" refId="ref27103" refString="Wilson LE. 1973. A delphinid Mammalia, Cetacea, from the Miocene of Palos Verdes Hills, California. University of California Publications in Geological Sciences 103: 1 - 34." type="journal article" year="1973">Wilson (1973)</bibRefCitation>
and 
<bibRefCitation author="Fordyce RE" box="[1148,1315,1354,1376]" pageId="9" pageNumber="1646" refId="ref23467" refString="Fordyce RE. 1978. The morphology and systematics of New Zealand fossil Cetacea. Unpublished D. Phil. Thesis, University of Canterbury." type="book" year="1978">Fordyce (1978)</bibRefCitation>
].
</paragraph>
<paragraph blockId="9.[827,1443,710,1897]" lastBlockId="10.[145,762,197,1905]" lastPageId="10" lastPageNumber="1647" pageId="9" pageNumber="1646">
The pars cochlearis is transversely compressed, with an anteroposterior length of 
<quantity box="[1160,1240,1416,1437]" metricMagnitude="-2" metricUnit="m" metricValue="3.3" pageId="9" pageNumber="1646" unit="mm" value="33.0">33 mm</quantity>
and a transverse breadth of 
<quantity box="[950,1051,1446,1468]" metricMagnitude="-2" metricUnit="m" metricValue="1.23" pageId="9" pageNumber="1646" unit="mm" value="12.3">12.3 mm</quantity>
. At the level of the fenestra ovalis, the pars cochlearis has a maximum dorsoventral depth of 
<quantity box="[857,963,1508,1530]" metricMagnitude="-2" metricUnit="m" metricValue="1.67" pageId="9" pageNumber="1646" unit="mm" value="16.7">16.7 mm</quantity>
; anteriorly, the pars cochlearis becomes shallower. The dorsal face of the pars cochlearis has been slightly damaged, but a rugose and concave surface can be discerned. The ventral surface of the pars cochlearis is convex, while the anteroventral face of the pars cochlearis is steeply convex and ascends anterodorsally. The posterior face of the pars cochlearis is subrectangular and is dominated by the fenestra rotunda, which opens dorsolateral and posterior to the fenestra ovalis and ventral foramen of the facial canal (
<figureCitation box="[903,983,1814,1836]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="9" pageNumber="1646">Fig. 4F</figureCitation>
). In posterior view, the fenestra rotunda has a subrounded profile and opens posteromedially; a subrounded fossa contains the fenestra rotunda. The dorsal margin of the fenestra rotunda, visible ventrally, shows multiple minute striations. A transversely (dorsoventrally) large and shallow groove is located on the medial surface of the pars cochlearis. Additionally, a minute tubercle projects posteromedially from the dorsomedial margin of the pars cochlearis, and it probably represents an insertion point for endocranial tissue. The groove is probably homologous with the median promontorial groove and runs parallel with the ventral margin of the pars cochlearis for nearly its entire medial length. The anterointernal angle of the pars cochlearis is distinct and angular, giving the pars cochlearis a subrectangular ventral profile (
<figureCitation box="[662,746,565,587]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="10" pageNumber="1647">Fig. 4A</figureCitation>
). A bulbous ridge, less developed than in basilosaurids, extends anteroposteriorly on the ventrolateral surface of the pars cochlearis. The anterior incisure forms a slit-like sulcus on the ventral surface of the periotic that posteriorly extends to the level of the anteromedial margin of the mallear fossa and anteriorly extends to the anterior margin of the pars cochlearis (
<figureCitation box="[661,745,780,802]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="10" pageNumber="1647">Fig. 4A</figureCitation>
). A prominent longitudinal and rounded ventral ridge on the medioventral surface of the pars cochlearis extends nearly the entire length of the pars cochlearis. The transversely compressed caudal tympanic process of the pars cochlearis is posteromedially oriented from the posteroventral margin of the pars cochlearis
</paragraph>
<paragraph blockId="10.[145,762,197,1905]" lastBlockId="10.[809,1425,197,1905]" pageId="10" pageNumber="1647">
The internal acoustic meatus has an ovoid profile in dorsal view and orients posteromedially– anterolaterally (
<figureCitation box="[334,416,1056,1078]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="10" pageNumber="1647">Fig. 4B</figureCitation>
). A low-lying rim outlines the internal acoustic meatus but has been destroyed along the lateral margin. The medial wall of the internal acoustic meatus ascends from the ventral and dorsal vestibular areas to produce a relatively deep internal acoustic meatus; the elevation of the lateral wall cannot be discerned, but it is similarly elevated as the medial wall in an undescribed putative kekenodontid (
<collectionCode box="[719,760,1270,1291]" country="New Zealand" name="Fossil Catalgoue in the Geology Museum" pageId="10" pageNumber="1647">OU</collectionCode>
22294). The diameter of the internal acoustic meatus increases dorsally, creating a funnel-like appearance. The ventral vestibular area is separated from the dorsal vestibular area by a low-lying transverse crest that is recessed 
<emphasis box="[335,353,1424,1445]" italics="true" pageId="10" pageNumber="1647">c.</emphasis>
<quantity box="[360,426,1424,1446]" metricMagnitude="-3" metricUnit="m" metricValue="6.0" pageId="10" pageNumber="1647" unit="mm" value="6.0">6 mm</quantity>
within the internal acoustic meatus. The opening for the proximal opening of the facial canal within the ventral vestibular area is ovoid and slightly tear-shaped. There is no evidence of a fissure at the anterior edge of the internal acoustic meatus, in addition to no indication of a developed hiatus fallopii. The foramen singulare, central foramen and spiral cribriform tract are located within the dorsal vestibular area. 
<bibRefCitation author="Ichishima H &amp; Kawabe S &amp; Sawamura H" box="[343,612,1669,1691]" pageId="10" pageNumber="1647" pagination="1792 - 1799" refId="ref24780" refString="Ichishima H, Kawabe S, Sawamura H. 2021. The so-called foramen singulare in cetacean periotics is actually the superior vestibular area. The Anatomical Record 304: 1792 - 1799." type="journal article" year="2021">
Ichishima 
<emphasis box="[470,529,1669,1691]" italics="true" pageId="10" pageNumber="1647">et al.</emphasis>
(2021)
</bibRefCitation>
identify the structure commonly labelled the foramen singulare in 
<taxonomicName authorityName="BRISSON" authorityYear="1762" box="[175,266,1730,1751]" class="Insecta" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="10" pageNumber="1647" phylum="Arthropoda" rank="order">Cetacea</taxonomicName>
as representing the dorsal vestibular area, with the ‘true’ foramen singulare opening closer to the ventral vestibular area. Here, our identification of the foramen singulare will remain until Micro-CT of the periotic reveals if the pathway of the posterior ampullary nerve, which runs through the foramen singulare, is homologous in 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[1131,1265,197,219]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="10" pageNumber="1647" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[1131,1149,198,219]" italics="true" pageId="10" pageNumber="1647">K</emphasis>
. 
<emphasis box="[1163,1265,198,219]" italics="true" pageId="10" pageNumber="1647">onamata</emphasis>
</taxonomicName>
. The foramen singulare is separated from the spiral cribriform tract by a low-lying transverse crest (identified as the perpendicular crest by 
<bibRefCitation author="Ichishima H &amp; Kawabe S &amp; Sawamura H" box="[1080,1332,289,311]" pageId="10" pageNumber="1647" pagination="1792 - 1799" refId="ref24780" refString="Ichishima H, Kawabe S, Sawamura H. 2021. The so-called foramen singulare in cetacean periotics is actually the superior vestibular area. The Anatomical Record 304: 1792 - 1799." type="journal article" year="2021">
Ichishima 
<emphasis box="[1204,1262,289,311]" italics="true" pageId="10" pageNumber="1647">et al.</emphasis>
, 2021
</bibRefCitation>
) that is recessed further relative to the crest separating the ventral and dorsal vestibular areas (
<emphasis box="[1222,1233,351,372]" italics="true" pageId="10" pageNumber="1647">c</emphasis>
. 
<quantity box="[1246,1313,350,371]" metricMagnitude="-3" metricUnit="m" metricValue="8.0" pageId="10" pageNumber="1647" unit="mm" value="8.0">8 mm</quantity>
). Relative to the ventral vestibular area, the dorsal vestibular area is larger, but shares a similar ovoid profile. All foramina and openings within the internal acoustic meatus are arranged in a relatively linear fashion; the foramen singulare is positioned anterolateral to the central foramen, and the proximal opening of the facial canal is positioned anterior to the foramen singulare and slightly anterolateral to the central foramen (
<figureCitation box="[817,900,626,648]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="10" pageNumber="1647">Fig. 4B</figureCitation>
). The aperture for the vestibular aqueduct is ovoid and large (maximum diameter of 
<quantity box="[1258,1323,657,678]" metricMagnitude="-3" metricUnit="m" metricValue="8.0" pageId="10" pageNumber="1647" unit="mm" value="8.0">8 mm</quantity>
) relative to the smaller (maximum diameter of 
<quantity box="[1273,1364,688,709]" metricMagnitude="-3" metricUnit="m" metricValue="2.4" pageId="10" pageNumber="1647" unit="mm" value="2.4">2.4 mm</quantity>
) and more subrounded aperture for the cochlear aqueduct. A groove located anteromedial to the aperture for the cochlear aqueduct extends between the medial edge of the internal acoustic meatus and the dorsal surface of the pars cochlearis and forms a small, circular fossa at the posteromedial corner of the internal acoustic meatus. A narrow and relatively deep groove on the medial side of the ridge separates the apertures for the vestibular and cochlear aqueducts. A slight dorsal projection from the pars cochlearis indicates the posteromedial border of the aperture for the cochlear aqueduct. The anterior border of the aperture for the cochlear aqueduct is denoted by a triangularshaped dorsal projection posterolateral to the internal acoustic meatus.
</paragraph>
<paragraph blockId="10.[809,1425,197,1905]" lastBlockId="11.[163,780,197,495]" lastPageId="11" lastPageNumber="1648" pageId="10" pageNumber="1647">
The superior process is reduced to a low-lying robust ridge that anteriorly and posteriorly rises to form the anterodorsal angle and posterodorsal angles, respectively (
<figureCitation box="[1045,1183,1270,1292]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="10" pageNumber="1647">Fig. 4C, D, F</figureCitation>
). In the 
<typeStatus box="[1279,1377,1270,1292]" pageId="10" pageNumber="1647">holotype</typeStatus>
, the anterodorsal angle is missing, while the posterodorsal angle is triangular and projects posterodorsally. The preserved posterodorsal section of the anterior process represents the highest point of elevation on the dorsal surface of the periotic. The suprameatal area is shallowly concave. 
<bibRefCitation author="Fordyce RE" box="[1156,1344,1454,1476]" pageId="10" pageNumber="1647" refId="ref23467" refString="Fordyce RE. 1978. The morphology and systematics of New Zealand fossil Cetacea. Unpublished D. Phil. Thesis, University of Canterbury." type="book" year="1978">Fordyce (1978)</bibRefCitation>
noted three distinct anteroposteriorly oriented sulci on the suprameatal area (
<figureCitation box="[1032,1116,1515,1537]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="10" pageNumber="1647">Fig. 4B</figureCitation>
). The medialmost channel is laterally adjacent to the anterior and lateral borders of the internal acoustic meatus. A second channel is located along the approximate anteroposterior midline of the suprameatal area. The path of this channel extends anterodorsally on to a broken section of posterior anterior process, while posteriorly the channel approximates the ventromedial margin of the triangular projection forming the posterodorsal angle. The lateralmost channel seemingly follows the superior process. Anteriorly, the channel terminates lateral to the broken section of posterodorsal anterior, and posteriorly terminates along the dorsolateral and ventrolateral margins of the projection forming the posterodorsal angle. The slit-like and dorsoventrally oriented posteroexternal sulcus is located posterolateral and ventral to the posterodorsal angle.
</paragraph>
<paragraph blockId="11.[163,780,197,495]" pageId="11" pageNumber="1648">
The posterior process is limited to a small anterior section with few distinct features (
<figureCitation box="[604,762,350,372]" captionStart="Figure 4" captionStartId="8.[147,226,1523,1545]" captionTargetBox="[159,1411,199,1481]" captionTargetId="figure-167@8.[156,1414,195,1484]" captionTargetPageId="8" captionText="Figure 4. Left periotic of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, ventral view. B, dorsal view. C, medial view. D, lateral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381122" httpUri="https://zenodo.org/record/7381122/files/figure.png" pageId="11" pageNumber="1648">Fig. 4C, D, F</figureCitation>
). A prominent keel of unknown origin is present at the preserved anteromedial margin of the posterior process and may represent the side of the bullar facet or the lateral margin of the stylomastoid fossa.
</paragraph>
<paragraph blockId="11.[163,779,536,1079]" pageId="11" pageNumber="1648">
<emphasis box="[163,244,536,557]" italics="true" pageId="11" pageNumber="1648">Stapes:</emphasis>
The left stapes was found in articulation with the fenestra ovalis and has since been prepared out, where it is now preserved isolated from the periotic (
<figureCitation box="[171,232,628,650]" captionStart="Figure 5" captionStartId="11.[164,244,1846,1868]" captionTargetBox="[168,1441,1434,1803]" captionTargetId="figure-750@11.[163,1446,1432,1807]" captionTargetPageId="11" captionText="Figure 5. Left stapes of Kekenodon onamata (NMNZ Ma 306). A, lateral view. B, medial view. C, ventral view. D, dorsal view." figureDoi="http://doi.org/10.5281/zenodo.7381124" httpUri="https://zenodo.org/record/7381124/files/figure.png" pageId="11" pageNumber="1648">Fig. 5</figureCitation>
). The footplate of the stapes broadens posteriorly and is anteriorly and laterally narrow. Additionally, the footplate of the stapes has a convex dorsal (vestibular) surface and a shallowly concave ventral surface. The stapedial foramen for the stapedial artery is subrounded and opens mediolaterally. The anterior crus is broader than the posterior crus and is positioned perpendicular to the footplate, while the posterior crus is at a slight angle to the footplate. The head of the stapes is large and squared off. A depression located on the anteroventral surface of the head of the stapes is for articulation with the crus longum of the incus (
<bibRefCitation author="Mead JG &amp; Fordyce RE" pageId="11" pageNumber="1648" pagination="1 - 248" refId="ref25816" refString="Mead JG, Fordyce RE. 2009. The therian skull: a lexicon with emphasis on the odontocetes. Smithsonian Contributions to Zoology 627: 1 - 248." type="journal article" year="2009">Mead &amp; Fordyce, 2009</bibRefCitation>
). The insertion for the stapedial muscle is on the medial and dorsal faces of the stapedial head, and partially along the posterior crus.
</paragraph>
<paragraph blockId="11.[163,779,1120,1387]" lastBlockId="11.[827,1443,197,1384]" pageId="11" pageNumber="1648">
<emphasis box="[163,353,1120,1141]" italics="true" pageId="11" pageNumber="1648">Tympanic bulla:</emphasis>
The incomplete left tympanic bulla is isolated from the skull (
<figureCitation box="[495,570,1150,1172]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="11" pageNumber="1648">Figs 1</figureCitation>
, 
<figureCitation box="[587,601,1150,1172]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">6</figureCitation>
; 
<tableCitation box="[617,708,1150,1172]" captionStart="Table 3" captionStartId="13.[164,228,196,217]" captionTargetBox="[163,1442,282,513]" captionTargetPageId="13" captionText="Table 3. Measurements (in mm) of the holotype left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Measurements taken to the nearest tenth of a millimetre. Asterisk (*) denotes incomplete measurements as preserved" pageId="11" pageNumber="1648">Table 3</tableCitation>
). The element is large and dense, with well-defined medial (inner posterior prominence) and lateral (outer posterior prominence) lobes. The tympanic bulla is damaged and lacks most of the outer lip and associated structures. The anterolateral section of the tympanic bulla has been lost, giving a cordate outline, with a tapering anterior margin and widening posterior margin (
<figureCitation box="[924,1034,197,219]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6A, B</figureCitation>
). However, more complete tympanic bullae in two undescribed putative kekenodontids (
<collectionCode box="[834,875,258,279]" country="New Zealand" name="Fossil Catalgoue in the Geology Museum" pageId="11" pageNumber="1648">OU</collectionCode>
22023 and 
<collectionCode box="[1019,1059,258,279]" country="New Zealand" name="Fossil Catalgoue in the Geology Museum" pageId="11" pageNumber="1648">OU</collectionCode>
22394) are rhomboidal-shaped, as in 
<taxonomicName box="[894,1072,289,311]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="11" pageNumber="1648" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
and 
<taxonomicName authorityName="Mitchell" authorityYear="1989" box="[1135,1435,289,310]" class="Mammalia" family="Llanocetidae" genus="Llanocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="11" pageNumber="1648" phylum="Chordata" rank="species" species="denticrenatus">
<emphasis box="[1135,1435,289,310]" italics="true" pageId="11" pageNumber="1648">Llanocetus denticrenatus</emphasis>
</taxonomicName>
, suggesting the complete tympanic bulla of 
<taxonomicName authorityName=", Hector" authorityYear="1881" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="11" pageNumber="1648" phylum="Chordata" rank="species" species="onamata">
<emphasis italics="true" pageId="11" pageNumber="1648">Kekenodon onamata</emphasis>
</taxonomicName>
had a similar profile. The medial margin is straight to slightly concave, while the lateral margin is convex (
<figureCitation box="[956,1077,412,434]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6C, D</figureCitation>
). Ventrally, the involucrum is separated from the outer lip by a distinct median furrow on the otherwise convex ventral surface (
<figureCitation box="[1296,1378,473,495]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6D</figureCitation>
). The median furrow is elongated and transversely narrow and extends for 
<emphasis box="[1022,1039,535,556]" italics="true" pageId="11" pageNumber="1648">c.</emphasis>
<quantity box="[1048,1150,534,556]" metricMagnitude="-2" metricUnit="m" metricValue="4.7299999999999995" pageId="11" pageNumber="1648" unit="mm" value="47.3">47.3 mm</quantity>
from the posterior limit of the bulla to just posterior to the level of the lateral furrow (
<figureCitation box="[917,1053,596,618]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6B, D, F</figureCitation>
); the ventralmost lateral furrow is preserved and is level with an ovoid fossa on the dorsal surface of the involucrum (
<figureCitation box="[1128,1207,657,679]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6C</figureCitation>
). The median furrow separates the inner and outer posterior prominences. The interprominential notch is the posterior continuation of the median furrow (
<bibRefCitation author="Kasuya T" box="[1231,1385,749,770]" pageId="11" pageNumber="1648" pagination="1 - 103" refId="ref24836" refString="Kasuya T. 1973. Systematic consideration of recent toothed whales based on the morphology of the tympano-periotic bone. Scientific Reports of the Whales Research Institute Tokyo 25: 1 - 103." type="journal article" year="1973">Kasuya, 1973</bibRefCitation>
) and is marked by a slight concavity in the posterior margin of the tympanic bulla (in dorsal view) just medial to the posteromedial margin of the outer posterior prominence (
<figureCitation box="[980,1062,871,893]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6F</figureCitation>
). The interprominential ridge is dorsolaterally oriented on the posterior surface of the tympanic bulla and is contiguous with the posterior extension of the involucral ridge from the ventromedial margin of the involucrum; the interprominential ridge terminates at the posterodorsal extension of the median furrow (
<figureCitation box="[1082,1170,1055,1077]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6F</figureCitation>
). The inner posterior prominence is broader relative to the transversely narrow outer posterior prominence and has greater dorsoventral depth (
<figureCitation box="[1074,1195,1147,1169]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="11" pageNumber="1648">Fig. 6C, D</figureCitation>
). The posteromedial margin of the inner posterior prominence is mostly rounded but does present a slight angularity due to the interprominential ridge. However, the angularity of the posteromedial margin of the inner posterior prominence is not as pronounced as in 
<taxonomicName box="[1267,1438,1301,1323]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="11" pageNumber="1648" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
, but is more angular relative to toothed and edentulous baleen-bearing mysticetes (Boessenecker &amp; Fordyce,
</paragraph>
<caption ID-DOI="http://doi.org/10.5281/zenodo.7381124" ID-Zenodo-Dep="7381124" httpUri="https://zenodo.org/record/7381124/files/figure.png" pageId="11" pageNumber="1648" startId="11.[164,244,1846,1868]" targetBox="[168,1441,1434,1803]" targetPageId="11">
<paragraph blockId="11.[163,1442,1846,1898]" pageId="11" pageNumber="1648">
<emphasis bold="true" box="[164,270,1846,1868]" pageId="11" pageNumber="1648">Figure 5.</emphasis>
Left stapes of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[432,648,1847,1869]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="11" pageNumber="1648" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[432,648,1847,1869]" italics="true" pageId="11" pageNumber="1648">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[663,824,1847,1869]" italics="true" pageId="11" pageNumber="1648">NMNZ Ma 306</emphasis>
). A, lateral view. B, medial view. C, ventral view. D, dorsal view.
</paragraph>
</caption>
<caption ID-DOI="http://doi.org/10.5281/zenodo.7381126" ID-Zenodo-Dep="7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="12" pageNumber="1649" startId="12.[145,224,1745,1767]" targetBox="[149,1427,196,1699]" targetPageId="12">
<paragraph blockId="12.[145,1425,1745,1796]" pageId="12" pageNumber="1649">
<emphasis bold="true" box="[145,250,1745,1767]" pageId="12" pageNumber="1649">Figure 6.</emphasis>
Left tympanic bulla of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[503,718,1745,1766]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="12" pageNumber="1649" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[503,718,1745,1766]" italics="true" pageId="12" pageNumber="1649">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[732,892,1745,1766]" italics="true" pageId="12" pageNumber="1649">NMNZ Ma 306</emphasis>
). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view.
</paragraph>
</caption>
<caption pageId="13" pageNumber="1650" startId="13.[164,228,196,217]" targetBox="[163,1442,282,513]" targetIsTable="true" targetPageId="13">
<paragraph blockId="13.[163,1398,196,247]" pageId="13" pageNumber="1650">
<emphasis bold="true" box="[164,254,196,217]" pageId="13" pageNumber="1650">Table 3.</emphasis>
Measurements (in mm) of the holotype left tympanic bulla of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[905,1118,196,218]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="13" pageNumber="1650" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[905,1118,196,218]" italics="true" pageId="13" pageNumber="1650">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[1132,1290,196,218]" italics="true" pageId="13" pageNumber="1650">NMNZ Ma 306</emphasis>
). Measurements taken to the nearest tenth of a millimetre. Asterisk (*) denotes incomplete measurements as preserved
</paragraph>
</caption>
<paragraph pageId="13" pageNumber="1650">
<table box="[163,1442,282,513]" gridcols="2" gridrows="8" pageId="13" pageNumber="1650">
<tr box="[163,1442,282,304]" gridrow="0" pageId="13" pageNumber="1650">
<th box="[163,1303,282,304]" gridcol="0" gridrow="0" pageId="13" pageNumber="1650">Anteroposterior length from anterior apex to posterior margin of outer posterior prominence</th>
<th box="[1386,1442,282,304]" gridcol="1" gridrow="0" pageId="13" pageNumber="1650">75.5*</th>
</tr>
<tr box="[163,1442,312,334]" gridrow="1" pageId="13" pageNumber="1650">
<td box="[163,1303,312,334]" gridcol="0" gridrow="1" pageId="13" pageNumber="1650">Anteroposterior length of involucrum from anterior apex of involucrum to posterior margin of inner posterior</td>
<td box="[1386,1442,312,334]" gridcol="1" gridrow="1" pageId="13" pageNumber="1650">70.2</td>
</tr>
<tr box="[163,1442,342,364]" gridrow="2" pageId="13" pageNumber="1650">
<td box="[163,1442,342,364]" colspan="2" colspanRight="1" gridcol="0" gridrow="2" pageId="13" pageNumber="1650">prominence</td>
</tr>
<tr box="[163,1442,372,394]" gridrow="3" pageId="13" pageNumber="1650">
<td box="[163,1303,372,394]" gridcol="0" gridrow="3" pageId="13" pageNumber="1650">Maximum distance from posteroventral edge of outer posterior prominence to preserved dorsal margin of</td>
<td box="[1386,1442,372,394]" gridcol="1" gridrow="3" pageId="13" pageNumber="1650">36.1*</td>
</tr>
<tr box="[163,1442,401,423]" gridrow="4" pageId="13" pageNumber="1650" rowspan-1="1">
<td box="[163,1303,401,423]" gridcol="0" gridrow="4" pageId="13" pageNumber="1650">sigmoid process</td>
</tr>
<tr box="[163,1442,431,453]" gridrow="5" pageId="13" pageNumber="1650">
<td box="[163,1303,431,453]" gridcol="0" gridrow="5" pageId="13" pageNumber="1650">Transverse width at level of sigmoid process</td>
<td box="[1386,1442,431,453]" gridcol="1" gridrow="5" pageId="13" pageNumber="1650">54.7*</td>
</tr>
<tr box="[163,1442,461,483]" gridrow="6" pageId="13" pageNumber="1650">
<td box="[163,1303,461,483]" gridcol="0" gridrow="6" pageId="13" pageNumber="1650">Maximum dorsoventral depth from preserved dorsal margin of sigmoid process to ventral margin of outer lip</td>
<td box="[1386,1442,461,483]" gridcol="1" gridrow="6" pageId="13" pageNumber="1650">12.0*</td>
</tr>
<tr box="[163,1442,491,513]" gridrow="7" pageId="13" pageNumber="1650">
<td box="[163,1303,491,513]" gridcol="0" gridrow="7" pageId="13" pageNumber="1650">Transverse width across inner and outer posterior prominences</td>
<td box="[1386,1442,491,513]" gridcol="1" gridrow="7" pageId="13" pageNumber="1650">50.6</td>
</tr>
</table>
</paragraph>
<paragraph blockId="13.[163,780,581,1891]" pageId="13" pageNumber="1650">
2015b). Although damaged, the posterolateral margin of the outer posterior prominence is sharply rounded due to the prominential ridge (
<emphasis box="[524,588,643,664]" italics="true" pageId="13" pageNumber="1650">sensu</emphasis>
<bibRefCitation author="Tsai CH &amp; Fordyce RE" pageId="13" pageNumber="1650" pagination="535 - 560" refId="ref26691" refString="Tsai CH, Fordyce RE. 2015. The earliest gulp-feeding mysticete (Cetacea: Mysticeti) From the Oligocene of New Zealand. Journal of Mammalian Evolution 22: 535 - 560." type="journal article" year="2015">Tsai &amp; Fordyce, 2015</bibRefCitation>
), which extends posteroventrally and laterally from the conical process (not preserved). The outer posterior prominence extends further posteriorly, but less ventrally than the inner posterior prominence (
<figureCitation box="[171,283,796,818]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6C, D</figureCitation>
).
</paragraph>
<paragraph blockId="13.[163,780,581,1891]" lastBlockId="13.[827,1443,581,1186]" pageId="13" pageNumber="1650">
The involucrum is robust and increases in dorsoventral depth posteriorly; the dorsal and ventral surfaces of the involucrum converge anteriorly (
<figureCitation captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6A, C–F</figureCitation>
). The ventral surface of the involucrum is convex, while the dorsal surface is predominantly convex, with a distinct transverse groove level with the anterior-half of the posterior segment of the tympanic cavity; the groove separates the involucrum into anterior and posterior segments. The posterior segment of the involucrum is more bulbous, transversely broad and anteroposteriorly long relative to the anterior segment. The surface of the posterior segment of the involucrum is convex and smooth. The surface of the anterior segment is convex and seemingly forms a narrow, dorsally projecting ridge. A prominent subrounded fossa is located medial to the tympanic cavity and is possibly confluent with the transverse groove dividing the involucrum (
<figureCitation captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6C</figureCitation>
). Additionally, the fossa may be continuous with a relatively broad and shallow groove running anteriorly into the anterior segment of the tympanic cavity. Subtle striations are present along the dorsal surface of the involucrum (
<figureCitation box="[383,465,1501,1523]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6C</figureCitation>
). Posteriorly, the striations orient mediolaterally, while becoming increasingly anteromedially and ventrally oriented anteriorly. An anteroposteriorly elongate ovoid depression is present on the ventromedial surface of the involucrum. In life, this depression would have closely approximated the medial edge of the basioccipital crest (
<bibRefCitation author="Boessenecker RW &amp; Fordyce RE" pageId="13" pageNumber="1650" pagination="607 - 660" refId="ref22413" refString="Boessenecker RW, Fordyce RE. 2015 b. A new genus and species of eomysticetids (Cetacea: Mysticeti) and a reinterpretation of ' Mauicetus ' lophocephalus Marples, 1956: transitional baleen whales from the upper Oligocene of New Zealand. Zoological Journal of the Linnean Society 175: 607 - 660." type="journal article" year="2015">Boessenecker &amp; Fordyce, 2015b</bibRefCitation>
) and possible pharyngeal crest (of 
<bibRefCitation author="Mead JG &amp; Fordyce RE" box="[163,414,1746,1768]" pageId="13" pageNumber="1650" pagination="1 - 248" refId="ref25816" refString="Mead JG, Fordyce RE. 2009. The therian skull: a lexicon with emphasis on the odontocetes. Smithsonian Contributions to Zoology 627: 1 - 248." type="journal article" year="2009">Mead &amp; Fordyce, 2009</bibRefCitation>
) more anteriorly. The involucral ridge expands the entire anteroposterior length of the medial surface of the involucrum and separates smooth bone (dorsally) from rugose bone (ventrally); the smooth bone dorsal to the involucral ridge (
<figureCitation box="[835,945,581,603]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6A, E</figureCitation>
) marks the position of the peribullary sinus (
<bibRefCitation author="Boessenecker RW &amp; Fordyce RE" box="[836,1228,612,634]" pageId="13" pageNumber="1650" pagination="107 - 140" refId="ref22372" refString="Boessenecker RW, Fordyce RE. 2015 a. A new eomysticetid (Mammalia: Cetacea) from the Late Oligocene of New Zealand and a re-evaluation of ' Mauicetus' waitakiensis. Papers in Paleontology 1: 107 - 140." type="journal article" year="2015">Boessenecker &amp; Fordyce, 2015a</bibRefCitation>
). Posteriorly, the involucral ridge extends through the ovoid depression and becomes contiguous with the interprominential ridge on the posterior surface of the inner posterior prominence (
<figureCitation box="[975,1055,734,756]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6F</figureCitation>
).
</paragraph>
<paragraph blockId="13.[827,1443,581,1186]" pageId="13" pageNumber="1650">
Remnants of the inner and outer posterior pedicles of the posterior process are located posteriorly and posterolaterally on the dorsal surface of the tympanic bulla (
<figureCitation box="[905,991,857,879]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6C</figureCitation>
). The inner posterior pedicle appears larger than the outer posterior pedicle but is obscured due to weathering. The inner and outer posterior pedicles of the posterior process of the tympanic bulla are visible in lateral view. The inner posterior pedicle is elevated more dorsally than the outer posterior pedicle. In posterior view, a distinct elliptical foramen is present, forming a distinct notch between the inner and outer posterior pedicles. The margins of the elliptical foramen are either missing or damaged, obscuring further morphological detail (
<figureCitation box="[1281,1361,1164,1186]" captionStart="Figure 6" captionStartId="12.[145,224,1745,1767]" captionTargetBox="[149,1427,196,1699]" captionTargetId="figure-26@12.[145,1428,195,1705]" captionTargetPageId="12" captionText="Figure 6. Left tympanic bulla of Kekenodon onamata (NMNZ Ma 306). Specimen whitened with ammonium chloride. A, medial view. B, lateral view. C, dorsal view. D, ventral view. E, anterior view. F, posterior view." figureDoi="http://doi.org/10.5281/zenodo.7381126" httpUri="https://zenodo.org/record/7381126/files/figure.png" pageId="13" pageNumber="1650">Fig. 6F</figureCitation>
).
</paragraph>
<paragraph blockId="13.[827,1443,1226,1892]" lastBlockId="14.[145,761,1266,1901]" lastPageId="14" lastPageNumber="1651" pageId="13" pageNumber="1650">
<emphasis box="[827,1217,1226,1248]" italics="true" pageId="13" pageNumber="1650">
Dentition: 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[971,1217,1226,1248]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="13" pageNumber="1650" phylum="Chordata" rank="species" species="onamata">Kekenodon onamata</taxonomicName>
</emphasis>
is heterodont. Six single-rooted teeth, six double-rooted teeth and two triple-rooted teeth are preserved isolated from the rostrum and mandible (
<figureCitation box="[1127,1204,1318,1340]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="13" pageNumber="1650">Figs 1</figureCitation>
, 
<figureCitation box="[1222,1236,1319,1340]" captionStart="Figure 7" captionStartId="14.[145,224,1147,1169]" captionTargetBox="[149,1421,199,1105]" captionTargetId="figure-377@14.[145,1425,195,1107]" captionTargetPageId="14" captionText="Figure 7. Single-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1." figureDoi="http://doi.org/10.5281/zenodo.7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="13" pageNumber="1650">7</figureCitation>
, 
<figureCitation box="[1254,1268,1318,1339]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="13" pageNumber="1650">8</figureCitation>
; 
<tableCitation box="[1284,1376,1318,1340]" captionStart="Table 4" captionStartId="16.[145,209,196,217]" captionTargetBox="[144,1415,371,867]" captionTargetPageId="16" captionText="Table 4. Measurements (in mm) of the holotype dentition of Kekenodon onamata (NMNZ Ma 306). Crown measurements taken to the nearest tenth of a millimetre. Asterisk (*) denotes incomplete measurements as preserved; (e) denotes estimated measurements. I = upper incisor, i = lower incisor; C/c = upper and lower canines, respectively; P/p = upper" pageId="13" pageNumber="1650">Table 4</tableCitation>
); the inferred left M1 and right p3 were curated at the 
<collectingCountry name="New Zealand" pageId="13" pageNumber="1650">New Zealand</collectingCountry>
Geological Survey (GS 476 CD 40/2 and GS 476 CD 40/1, respectively), but have since been referred to the 
<typeStatus box="[906,1008,1441,1463]" pageId="13" pageNumber="1650">holotype</typeStatus>
specimen (
<emphasis box="[1146,1327,1441,1463]" italics="true" pageId="13" pageNumber="1650">
<collectionCode box="[1146,1228,1442,1463]" country="New Zealand" httpUri="http://grbio.org/cool/fg7h-t7tk" name="Museum of New Zealand Te Papa Tongarewa" pageId="13" pageNumber="1650" type="Museum">NMNZ</collectionCode>
Ma 306
</emphasis>
; 
<bibRefCitation author="Fordyce RE" pageId="13" pageNumber="1650" pagination="319 - 336" refId="ref23493" refString="Fordyce RE. 1980. Whale evolution and Oligocene Southern Ocean environments. Palaeogeography, Palaeoclimatology, Palaeoecology 31: 319 - 336." type="journal article" year="1980">Fordyce, 1980</bibRefCitation>
). Morphological characteristics (e.g. infilled pulp cavities) indicate that all teeth probably represent permanent dentition. The absence of preserved rostrum and mandibles obscures any evidence of possible dental eruption. Thus, it is uncertain whether 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[1305,1443,1595,1616]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="13" pageNumber="1650" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[1305,1323,1595,1616]" italics="true" pageId="13" pageNumber="1650">K</emphasis>
. 
<emphasis box="[1339,1443,1595,1616]" italics="true" pageId="13" pageNumber="1650">onamata</emphasis>
</taxonomicName>
was monophyodont or diphyodont. Tooth positions and numbers are tentatively identified with reference to previous observations by 
<bibRefCitation author="Hector J" box="[1113,1267,1686,1708]" pageId="13" pageNumber="1650" pagination="434 - 436" refId="ref24521" refString="Hector J. 1881. Notes on New Zealand Cetacea, recent and fossil. Transactions of the New Zealand Institute 13: 434 - 436." type="journal article" year="1881">Hector (1881)</bibRefCitation>
, 
<bibRefCitation author="Kellogg AR" box="[1279,1443,1686,1708]" pageId="13" pageNumber="1650" pagination="1 - 366" refId="ref24941" refString="Kellogg AR. 1936. A review of the Archaeoceti. Carnegie Institute of Washington Publication 482: 1 - 366." type="journal article" year="1936">Kellogg (1936)</bibRefCitation>
and 
<bibRefCitation author="Fordyce RE" box="[879,1053,1717,1739]" pageId="13" pageNumber="1650" refId="ref23467" refString="Fordyce RE. 1978. The morphology and systematics of New Zealand fossil Cetacea. Unpublished D. Phil. Thesis, University of Canterbury." type="book" year="1978">Fordyce (1978)</bibRefCitation>
, in concert with reference to the crown and root morphology (e.g. profile of crown and number of roots) of 
<taxonomicName box="[1049,1221,1778,1800]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="13" pageNumber="1650" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
. The absence of the rostrum and mandibles makes all tooth identifications provisional. The dental formula is uncertain, but with comparisons to the well-preserved skull of the provisional kekenodontid 
<collectionCode box="[460,500,1266,1287]" country="New Zealand" name="Fossil Catalgoue in the Geology Museum" pageId="14" pageNumber="1651">OU</collectionCode>
22294, it is proposed here that 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[259,392,1297,1318]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="14" pageNumber="1651" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[259,277,1297,1318]" italics="true" pageId="14" pageNumber="1651">K</emphasis>
. 
<emphasis box="[291,392,1297,1318]" italics="true" pageId="14" pageNumber="1651">onamata</emphasis>
</taxonomicName>
retained the basilosaurid count of 3142/3143.
</paragraph>
<caption ID-DOI="http://doi.org/10.5281/zenodo.7381128" ID-Zenodo-Dep="7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="14" pageNumber="1651" startId="14.[145,224,1147,1169]" targetBox="[149,1421,199,1105]" targetPageId="14">
<paragraph blockId="14.[145,1425,1147,1228]" pageId="14" pageNumber="1651">
<emphasis bold="true" box="[145,250,1147,1169]" pageId="14" pageNumber="1651">Figure 7.</emphasis>
Single-rooted teeth of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[497,711,1147,1169]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="14" pageNumber="1651" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[497,711,1147,1169]" italics="true" pageId="14" pageNumber="1651">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[726,886,1147,1169]" italics="true" pageId="14" pageNumber="1651">NMNZ Ma 306</emphasis>
) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1.
</paragraph>
</caption>
<paragraph blockId="14.[145,761,1266,1901]" lastBlockId="14.[809,1425,1266,1901]" pageId="14" pageNumber="1651">
The single-rooted teeth are caniniform, having a subconical profile with a diameter that tapers toward the apex (
<figureCitation box="[257,327,1419,1441]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="14" pageNumber="1651">Figs 1</figureCitation>
, 
<figureCitation box="[340,354,1420,1441]" captionStart="Figure 7" captionStartId="14.[145,224,1147,1169]" captionTargetBox="[149,1421,199,1105]" captionTargetId="figure-377@14.[145,1425,195,1107]" captionTargetPageId="14" captionText="Figure 7. Single-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1." figureDoi="http://doi.org/10.5281/zenodo.7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="14" pageNumber="1651">7</figureCitation>
). Two nearly complete crowns of an inferred left C1 (
<figureCitation box="[338,420,1450,1472]" captionStart="Figure 7" captionStartId="14.[145,224,1147,1169]" captionTargetBox="[149,1421,199,1105]" captionTargetId="figure-377@14.[145,1425,195,1107]" captionTargetPageId="14" captionText="Figure 7. Single-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1." figureDoi="http://doi.org/10.5281/zenodo.7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="14" pageNumber="1651">Fig. 7C</figureCitation>
) and right c1 (
<figureCitation box="[592,675,1450,1472]" captionStart="Figure 7" captionStartId="14.[145,224,1147,1169]" captionTargetBox="[149,1421,199,1105]" captionTargetId="figure-377@14.[145,1425,195,1107]" captionTargetPageId="14" captionText="Figure 7. Single-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1." figureDoi="http://doi.org/10.5281/zenodo.7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="14" pageNumber="1651">Fig. 7D</figureCitation>
), and a partial crown of an inferred incisor or canine (
<figureCitation box="[666,746,1480,1502]" captionStart="Figure 7" captionStartId="14.[145,224,1147,1169]" captionTargetBox="[149,1421,199,1105]" captionTargetId="figure-377@14.[145,1425,195,1107]" captionTargetPageId="14" captionText="Figure 7. Single-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1." figureDoi="http://doi.org/10.5281/zenodo.7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="14" pageNumber="1651">Fig. 7B</figureCitation>
), are lingually concave and recurved and lack accessory denticles. Distinct anterior and posterior carinae are present on all caniniform crowns and are not crenulated. The enamel on the lingual surface of the crowns is ornamented with prominent anastomosing longitudinal ridges. The ridges are absent from the labial surface where the enamel is smooth with a slight wrinkled texture. There is no evidence of a developed ecto- or entocingulum. An additional single-rooted tooth preserves a small portion of the basolingual section of the crown with an associated single root (
<figureCitation box="[154,239,1848,1870]" captionStart="Figure 7" captionStartId="14.[145,224,1147,1169]" captionTargetBox="[149,1421,199,1105]" captionTargetId="figure-377@14.[145,1425,195,1107]" captionTargetPageId="14" captionText="Figure 7. Single-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1." figureDoi="http://doi.org/10.5281/zenodo.7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="14" pageNumber="1651">Fig. 7E</figureCitation>
). The crown was damaged during the early 1980s and lacks morphological detail. However, a more complete version of the crown was figured in 
<bibRefCitation author="Fordyce RE" pageId="14" pageNumber="1651" refId="ref23467" refString="Fordyce RE. 1978. The morphology and systematics of New Zealand fossil Cetacea. Unpublished D. Phil. Thesis, University of Canterbury." type="book" year="1978">Fordyce (1978: 663</bibRefCitation>
, figs 148–151), indicating a subconical crown. It is unclear whether p1 was denticulate. 
<bibRefCitation author="Fordyce RE" box="[809,985,1358,1380]" pageId="14" pageNumber="1651" refId="ref23467" refString="Fordyce RE. 1978. The morphology and systematics of New Zealand fossil Cetacea. Unpublished D. Phil. Thesis, University of Canterbury." type="book" year="1978">Fordyce (1978)</bibRefCitation>
provisionally identified the tooth as a left p1. Subhorizontal abrasive (formed by tooth/ food contact) apical wear facets are present on all caniniform crowns. The enamel surrounding the wear facets is smooth, contrasting with the longitudinal ridges that ornament the remainder of the lingual surface of the crown. Elongate longitudinal sections of broken enamel are located on the labial surface of all crowns and the lingual surface of the partial crown with wear exposing windows of underlying dentin.
</paragraph>
<paragraph blockId="14.[809,1425,1266,1901]" lastBlockId="16.[145,762,926,1899]" lastPageId="16" lastPageNumber="1653" pageId="14" pageNumber="1651">
The associated roots of C1 and c1 are elongate, inflated and have a sigmoidal profile in dorsal and ventral views. All surfaces of the roots are convex, with vascular sulci present throughout. The roots are widest and inflated near midlength. Posteriorly, the diameter of the root markedly decreases. The preserved posterior-half of the roots have an elongate ovoid cross-section, while towards the crown, the cross-section becomes increasingly circular. A large fragment of a single root without an associated crown is similarly elongate and inflated (
<figureCitation box="[611,701,1585,1607]" captionStart="Figure 7" captionStartId="14.[145,224,1147,1169]" captionTargetBox="[149,1421,199,1105]" captionTargetId="figure-377@14.[145,1425,195,1107]" captionTargetPageId="14" captionText="Figure 7. Single-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, isolated root of a presumed incisor or canine. B, presumed incisor or canine. C, presumed left C1. D, presumed right c1. E, presumed left p1." figureDoi="http://doi.org/10.5281/zenodo.7381128" httpUri="https://zenodo.org/record/7381128/files/figure.png" pageId="15" pageNumber="1652">Fig. 7A</figureCitation>
). One surface of the root is planar to slightly concave, with a prominent anteroposteriorly oriented groove, perhaps vascular, that extends the entire preserved length. The anteriormost and posteriormost sections of the root are missing, which would have probably revealed a sigmoidal profile in anterior and posterior views. Similar to C1 and c1, the root has an anteroposteriorly elongate ovoid cross-section that is widest near the preserved posterior margin or, if complete, at the approximate midlength of the root. Here, the root is inflated as in C1 and c1. The diameter of the root decreases anteriorly. The morphological similarities of the root fragment relative to C1 and c1, in concert with being proportionally smaller, suggests the single root is associated with a more anterior incisor. The associated root of p1 is proportionally smaller relative to C1 and c1 and the root fragment. The subvertical and slightly anterior orientation of the root indicates a more posterior position in the lower tooth row. The apicalthird of the root is moderately inflated. A narrow and shallow (slit-like) sulcus is anteroposteriorly oriented and bisects the posterior surface of the root into labial and lingual lobes, suggesting p1 is morphologically intermediate between single- and double-rooted teeth.
</paragraph>
<caption ID-DOI="http://doi.org/10.5281/zenodo.7381130" ID-Zenodo-Dep="7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="15" pageNumber="1652" startId="15.[163,241,1376,1398]" targetBox="[165,1437,198,1331]" targetPageId="15">
<paragraph blockId="15.[163,1442,1376,1486]" pageId="15" pageNumber="1652">
<emphasis bold="true" box="[163,267,1376,1398]" pageId="15" pageNumber="1652">Figure 8.</emphasis>
Double-rooted teeth of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[515,727,1376,1398]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="15" pageNumber="1652" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[515,727,1376,1398]" italics="true" pageId="15" pageNumber="1652">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[740,898,1376,1398]" italics="true" pageId="15" pageNumber="1652">NMNZ Ma 306</emphasis>
) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear.
</paragraph>
</caption>
<caption pageId="16" pageNumber="1653" startId="16.[145,209,196,217]" targetBox="[144,1415,371,867]" targetIsTable="true" targetPageId="16">
<paragraph blockId="16.[145,1418,196,335]" pageId="16" pageNumber="1653">
<emphasis bold="true" box="[145,235,196,217]" pageId="16" pageNumber="1653">Table 4.</emphasis>
Measurements (in mm) of the holotype dentition of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[784,996,196,218]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[784,996,196,218]" italics="true" pageId="16" pageNumber="1653">Kekenodon onamata</emphasis>
</taxonomicName>
(
<emphasis box="[1010,1169,196,218]" italics="true" pageId="16" pageNumber="1653">NMNZ Ma 306</emphasis>
). Crown measurements taken to the nearest tenth of a millimetre. Asterisk (*) denotes incomplete measurements as preserved; (e) denotes estimated measurements. I = upper incisor, i = lower incisor; C/c = upper and lower canines, respectively; P/p = upper and lower premolars, respectively; M/m = upper and lower molars, respectively. All numbers next to these indicate provisionally identified tooth position.
</paragraph>
</caption>
<paragraph pageId="16" pageNumber="1653">
<table box="[144,1415,371,867]" gridcols="7" gridrows="16" pageId="16" pageNumber="1653">
<tr box="[144,1415,371,393]" gridrow="0" pageId="16" pageNumber="1653">
<th box="[144,237,371,393]" gridcol="0" gridrow="0" pageId="16" pageNumber="1653">Tooth ID</th>
<th box="[327,470,371,393]" gridcol="1" gridrow="0" pageId="16" pageNumber="1653">Crown length</th>
<th box="[525,668,371,393]" gridcol="2" gridrow="0" pageId="16" pageNumber="1653">Crown height</th>
<th box="[723,858,371,393]" gridcol="3" gridrow="0" pageId="16" pageNumber="1653">Crown width</th>
<th box="[920,979,371,393]" gridcol="4" gridrow="0" pageId="16" pageNumber="1653">Roots</th>
<th box="[1118,1217,371,393]" gridcol="5" gridrow="0" pageId="16" pageNumber="1653">Anterior</th>
<th box="[1316,1415,371,393]" gridcol="6" gridrow="0" pageId="16" pageNumber="1653">Posterior</th>
</tr>
<tr box="[144,1415,400,422]" gridrow="1" pageId="16" pageNumber="1653" rowspan-0="1" rowspan-1="1" rowspan-2="1" rowspan-3="1" rowspan-4="1">
<td box="[1118,1217,400,422]" gridcol="5" gridrow="1" pageId="16" pageNumber="1653">accessory</td>
<td box="[1316,1415,400,422]" gridcol="6" gridrow="1" pageId="16" pageNumber="1653">accessory</td>
</tr>
<tr box="[144,1415,430,452]" gridrow="2" pageId="16" pageNumber="1653" rowspan-0="1" rowspan-1="1" rowspan-2="1" rowspan-3="1" rowspan-4="1">
<td box="[1118,1217,430,452]" gridcol="5" gridrow="2" pageId="16" pageNumber="1653">denticles</td>
<td box="[1316,1415,430,452]" gridcol="6" gridrow="2" pageId="16" pageNumber="1653">denticles</td>
</tr>
<tr box="[144,1415,485,507]" gridrow="3" pageId="16" pageNumber="1653">
<th box="[144,237,485,507]" gridcol="0" gridrow="3" pageId="16" pageNumber="1653">I1–3/C1</th>
<td box="[327,470,485,507]" gridcol="1" gridrow="3" pageId="16" pageNumber="1653">17.1*</td>
<td box="[525,668,485,507]" gridcol="2" gridrow="3" pageId="16" pageNumber="1653">23.8*</td>
<td box="[723,858,485,507]" gridcol="3" gridrow="3" pageId="16" pageNumber="1653">16.3*</td>
<td box="[920,979,485,507]" gridcol="4" gridrow="3" pageId="16" pageNumber="1653">1</td>
<td box="[1118,1217,485,507]" gridcol="5" gridrow="3" pageId="16" pageNumber="1653">0</td>
<td box="[1316,1415,485,507]" gridcol="6" gridrow="3" pageId="16" pageNumber="1653">0</td>
</tr>
<tr box="[144,1415,515,537]" gridrow="4" pageId="16" pageNumber="1653">
<th box="[144,237,515,537]" gridcol="0" gridrow="4" pageId="16" pageNumber="1653">C1</th>
<td box="[327,470,515,537]" gridcol="1" gridrow="4" pageId="16" pageNumber="1653">22.7</td>
<td box="[525,668,515,537]" gridcol="2" gridrow="4" pageId="16" pageNumber="1653">46.8*</td>
<td box="[723,858,515,537]" gridcol="3" gridrow="4" pageId="16" pageNumber="1653">21.7</td>
<td box="[920,979,515,537]" gridcol="4" gridrow="4" pageId="16" pageNumber="1653">1</td>
<td box="[1118,1217,515,537]" gridcol="5" gridrow="4" pageId="16" pageNumber="1653">0</td>
<td box="[1316,1415,515,537]" gridcol="6" gridrow="4" pageId="16" pageNumber="1653">0</td>
</tr>
<tr box="[144,1415,545,567]" gridrow="5" pageId="16" pageNumber="1653">
<th box="[144,237,545,567]" gridcol="0" gridrow="5" pageId="16" pageNumber="1653">P2</th>
<td box="[327,470,545,567]" gridcol="1" gridrow="5" pageId="16" pageNumber="1653">43</td>
<td box="[525,668,545,567]" gridcol="2" gridrow="5" pageId="16" pageNumber="1653">–</td>
<td box="[723,858,545,567]" gridcol="3" gridrow="5" pageId="16" pageNumber="1653">19</td>
<td box="[920,979,545,567]" gridcol="4" gridrow="5" pageId="16" pageNumber="1653">2</td>
<td box="[1118,1217,545,567]" gridcol="5" gridrow="5" pageId="16" pageNumber="1653">4 (e)</td>
<td box="[1316,1415,545,567]" gridcol="6" gridrow="5" pageId="16" pageNumber="1653">5</td>
</tr>
<tr box="[144,1415,575,597]" gridrow="6" pageId="16" pageNumber="1653">
<th box="[144,237,575,597]" gridcol="0" gridrow="6" pageId="16" pageNumber="1653">P3</th>
<td box="[327,470,575,597]" gridcol="1" gridrow="6" pageId="16" pageNumber="1653">32.4</td>
<td box="[525,668,575,597]" gridcol="2" gridrow="6" pageId="16" pageNumber="1653">34.5*</td>
<td box="[723,858,575,597]" gridcol="3" gridrow="6" pageId="16" pageNumber="1653">21.7</td>
<td box="[920,979,575,597]" gridcol="4" gridrow="6" pageId="16" pageNumber="1653">3</td>
<td box="[1118,1217,575,597]" gridcol="5" gridrow="6" pageId="16" pageNumber="1653">4</td>
<td box="[1316,1415,575,597]" gridcol="6" gridrow="6" pageId="16" pageNumber="1653">4</td>
</tr>
<tr box="[144,1415,605,627]" gridrow="7" pageId="16" pageNumber="1653">
<th box="[144,237,605,627]" gridcol="0" gridrow="7" pageId="16" pageNumber="1653">P4</th>
<td box="[327,470,605,627]" gridcol="1" gridrow="7" pageId="16" pageNumber="1653">32.7</td>
<td box="[525,668,605,627]" gridcol="2" gridrow="7" pageId="16" pageNumber="1653">23.5*</td>
<td box="[723,858,605,627]" gridcol="3" gridrow="7" pageId="16" pageNumber="1653">21.7</td>
<td box="[920,979,605,627]" gridcol="4" gridrow="7" pageId="16" pageNumber="1653">3</td>
<td box="[1118,1217,605,627]" gridcol="5" gridrow="7" pageId="16" pageNumber="1653">4 (e)</td>
<td box="[1316,1415,605,627]" gridcol="6" gridrow="7" pageId="16" pageNumber="1653">5</td>
</tr>
<tr box="[144,1415,635,657]" gridrow="8" pageId="16" pageNumber="1653">
<th box="[144,237,635,657]" gridcol="0" gridrow="8" pageId="16" pageNumber="1653">M1</th>
<td box="[327,470,635,657]" gridcol="1" gridrow="8" pageId="16" pageNumber="1653">–</td>
<td box="[525,668,635,657]" gridcol="2" gridrow="8" pageId="16" pageNumber="1653">–</td>
<td box="[723,858,635,657]" gridcol="3" gridrow="8" pageId="16" pageNumber="1653">–</td>
<td box="[920,979,635,657]" gridcol="4" gridrow="8" pageId="16" pageNumber="1653">2</td>
<td box="[1118,1217,635,657]" gridcol="5" gridrow="8" pageId="16" pageNumber="1653">–</td>
<td box="[1316,1415,635,657]" gridcol="6" gridrow="8" pageId="16" pageNumber="1653">4</td>
</tr>
<tr box="[144,1415,665,687]" gridrow="9" pageId="16" pageNumber="1653">
<th box="[144,237,665,687]" gridcol="0" gridrow="9" pageId="16" pageNumber="1653">c1</th>
<td box="[327,470,665,687]" gridcol="1" gridrow="9" pageId="16" pageNumber="1653">21.7</td>
<td box="[525,668,665,687]" gridcol="2" gridrow="9" pageId="16" pageNumber="1653">38.2*</td>
<td box="[723,858,665,687]" gridcol="3" gridrow="9" pageId="16" pageNumber="1653">20.3</td>
<td box="[920,979,665,687]" gridcol="4" gridrow="9" pageId="16" pageNumber="1653">1</td>
<td box="[1118,1217,665,687]" gridcol="5" gridrow="9" pageId="16" pageNumber="1653">0</td>
<td box="[1316,1415,665,687]" gridcol="6" gridrow="9" pageId="16" pageNumber="1653">0</td>
</tr>
<tr box="[144,1415,695,717]" gridrow="10" pageId="16" pageNumber="1653">
<th box="[144,237,695,717]" gridcol="0" gridrow="10" pageId="16" pageNumber="1653">p1</th>
<td box="[327,470,695,717]" gridcol="1" gridrow="10" pageId="16" pageNumber="1653">–</td>
<td box="[525,668,695,717]" gridcol="2" gridrow="10" pageId="16" pageNumber="1653">–</td>
<td box="[723,858,695,717]" gridcol="3" gridrow="10" pageId="16" pageNumber="1653">–</td>
<td box="[920,979,695,717]" gridcol="4" gridrow="10" pageId="16" pageNumber="1653">1</td>
<td box="[1118,1217,695,717]" gridcol="5" gridrow="10" pageId="16" pageNumber="1653">–</td>
<td box="[1316,1415,695,717]" gridcol="6" gridrow="10" pageId="16" pageNumber="1653">–</td>
</tr>
<tr box="[144,1415,725,747]" gridrow="11" pageId="16" pageNumber="1653">
<th box="[144,237,725,747]" gridcol="0" gridrow="11" pageId="16" pageNumber="1653">p2</th>
<td box="[327,470,725,747]" gridcol="1" gridrow="11" pageId="16" pageNumber="1653">36.2</td>
<td box="[525,668,725,747]" gridcol="2" gridrow="11" pageId="16" pageNumber="1653">26.2*</td>
<td box="[723,858,725,747]" gridcol="3" gridrow="11" pageId="16" pageNumber="1653">18.8</td>
<td box="[920,979,725,747]" gridcol="4" gridrow="11" pageId="16" pageNumber="1653">2</td>
<td box="[1118,1217,725,747]" gridcol="5" gridrow="11" pageId="16" pageNumber="1653">4</td>
<td box="[1316,1415,725,747]" gridcol="6" gridrow="11" pageId="16" pageNumber="1653">5</td>
</tr>
<tr box="[144,1415,755,777]" gridrow="12" pageId="16" pageNumber="1653">
<th box="[144,237,755,777]" gridcol="0" gridrow="12" pageId="16" pageNumber="1653">p3</th>
<td box="[327,470,755,777]" gridcol="1" gridrow="12" pageId="16" pageNumber="1653">–</td>
<td box="[525,668,755,777]" gridcol="2" gridrow="12" pageId="16" pageNumber="1653">–</td>
<td box="[723,858,755,777]" gridcol="3" gridrow="12" pageId="16" pageNumber="1653">–</td>
<td box="[920,979,755,777]" gridcol="4" gridrow="12" pageId="16" pageNumber="1653">2</td>
<td box="[1118,1217,755,777]" gridcol="5" gridrow="12" pageId="16" pageNumber="1653">5</td>
<td box="[1316,1415,755,777]" gridcol="6" gridrow="12" pageId="16" pageNumber="1653">6</td>
</tr>
<tr box="[144,1415,785,807]" gridrow="13" pageId="16" pageNumber="1653">
<th box="[144,237,785,807]" gridcol="0" gridrow="13" pageId="16" pageNumber="1653">p4</th>
<td box="[327,470,785,807]" gridcol="1" gridrow="13" pageId="16" pageNumber="1653">36.1</td>
<td box="[525,668,785,807]" gridcol="2" gridrow="13" pageId="16" pageNumber="1653">36.9*</td>
<td box="[723,858,785,807]" gridcol="3" gridrow="13" pageId="16" pageNumber="1653">16.6*</td>
<td box="[920,979,785,807]" gridcol="4" gridrow="13" pageId="16" pageNumber="1653">2</td>
<td box="[1118,1217,785,807]" gridcol="5" gridrow="13" pageId="16" pageNumber="1653">4</td>
<td box="[1316,1415,785,807]" gridcol="6" gridrow="13" pageId="16" pageNumber="1653">5</td>
</tr>
<tr box="[144,1415,815,837]" gridrow="14" pageId="16" pageNumber="1653">
<th box="[144,237,815,837]" gridcol="0" gridrow="14" pageId="16" pageNumber="1653">m1</th>
<td box="[327,470,815,837]" gridcol="1" gridrow="14" pageId="16" pageNumber="1653">37.7*</td>
<td box="[525,668,815,837]" gridcol="2" gridrow="14" pageId="16" pageNumber="1653">32*</td>
<td box="[723,858,815,837]" gridcol="3" gridrow="14" pageId="16" pageNumber="1653">18.9</td>
<td box="[920,979,815,837]" gridcol="4" gridrow="14" pageId="16" pageNumber="1653">2</td>
<td box="[1118,1217,815,837]" gridcol="5" gridrow="14" pageId="16" pageNumber="1653">≥4</td>
<td box="[1316,1415,815,837]" gridcol="6" gridrow="14" pageId="16" pageNumber="1653">&gt;4</td>
</tr>
<tr box="[144,1415,845,867]" gridrow="15" pageId="16" pageNumber="1653">
<th box="[144,237,845,867]" gridcol="0" gridrow="15" pageId="16" pageNumber="1653">m2</th>
<td box="[327,470,845,867]" gridcol="1" gridrow="15" pageId="16" pageNumber="1653">26.9*</td>
<td box="[525,668,845,867]" gridcol="2" gridrow="15" pageId="16" pageNumber="1653">24.8*</td>
<td box="[723,858,845,867]" gridcol="3" gridrow="15" pageId="16" pageNumber="1653">14.7</td>
<td box="[920,979,845,867]" gridcol="4" gridrow="15" pageId="16" pageNumber="1653">2</td>
<td box="[1118,1217,845,867]" gridcol="5" gridrow="15" pageId="16" pageNumber="1653">≥2</td>
<td box="[1316,1415,845,867]" gridcol="6" gridrow="15" pageId="16" pageNumber="1653">4</td>
</tr>
</table>
</paragraph>
<paragraph blockId="16.[145,762,926,1899]" pageId="16" pageNumber="1653">
Subrounded holes around the enamel–cementum junction in C1 and throughout all surfaces of the root in c1 are probably indications of the osteophagous worm 
<taxonomicName authority="Rouse et al., 2004" authorityName="Rouse" authorityYear="2004" box="[145,454,1110,1132]" class="Polychaeta" family="Siboglinidae" genus="Osedax" kingdom="Animalia" order="Sabellida" pageId="16" pageNumber="1653" phylum="Annelida" rank="genus">
<emphasis box="[145,231,1110,1131]" italics="true" pageId="16" pageNumber="1653">Osedax</emphasis>
<bibRefCitation author="Rouse GW &amp; Goffredi SK &amp; Vrijenhoek RC" box="[240,454,1110,1132]" pageId="16" pageNumber="1653" pagination="668 - 671" refId="ref26251" refString="Rouse GW, Goffredi SK, and Vrijenhoek RC. 2004. Osedax: bone-eating marine worms with dwarf males. Science 305: 668 - 671." type="journal article" year="2004">
Rouse 
<emphasis box="[321,374,1110,1132]" italics="true" pageId="16" pageNumber="1653">et al</emphasis>
., 2004
</bibRefCitation>
</taxonomicName>
(Annelida: 
<taxonomicName box="[597,749,1110,1132]" class="Polychaeta" family="Siboglinidae" kingdom="Animalia" order="Sabellida" pageId="16" pageNumber="1653" phylum="Annelida" rank="family">Siboglinidae</taxonomicName>
). Small, circular holes on the root in c1 have a diameter between 2.0 and 
<quantity box="[345,434,1172,1194]" metricMagnitude="-3" metricUnit="m" metricValue="2.5" pageId="16" pageNumber="1653" unit="mm" value="2.5">2.5 mm</quantity>
, while larger pockmarks on the labial surface of the root have a diameter between 3 and 
<quantity box="[216,282,1233,1255]" metricMagnitude="-3" metricUnit="m" metricValue="6.0" pageId="16" pageNumber="1653" unit="mm" value="6.0">6 mm</quantity>
. The labial surface of the root has a large, subrounded depression (maximum diameter of 
<emphasis box="[743,761,1264,1285]" italics="true" pageId="16" pageNumber="1653">c.</emphasis>
<quantity box="[145,224,1294,1315]" metricMagnitude="-2" metricUnit="m" metricValue="2.8" pageId="16" pageNumber="1653" unit="mm" value="28.0">28 mm</quantity>
) that has been significantly bioeroded. Smaller circular depressions (diameters range between 2 and 
<quantity box="[145,225,1356,1377]" metricMagnitude="-2" metricUnit="m" metricValue="1.2" pageId="16" pageNumber="1653" unit="mm" value="12.0">12 mm</quantity>
) within the larger depression are possibly the result of collapsed 
<taxonomicName box="[366,450,1386,1407]" class="Polychaeta" family="Siboglinidae" genus="Osedax" kingdom="Animalia" order="Sabellida" pageId="16" pageNumber="1653" phylum="Annelida" rank="genus">
<emphasis box="[366,450,1386,1407]" italics="true" pageId="16" pageNumber="1653">Osedax</emphasis>
</taxonomicName>
galleries (
<bibRefCitation author="Boessenecker RW &amp; Fordyce RE" pageId="16" pageNumber="1653" pagination="107 - 140" refId="ref22372" refString="Boessenecker RW, Fordyce RE. 2015 a. A new eomysticetid (Mammalia: Cetacea) from the Late Oligocene of New Zealand and a re-evaluation of ' Mauicetus' waitakiensis. Papers in Paleontology 1: 107 - 140." type="journal article" year="2015">Boessenecker &amp; Fordyce, 2015a</bibRefCitation>
, d). Previously, 
<taxonomicName box="[497,580,1417,1438]" class="Polychaeta" family="Siboglinidae" genus="Osedax" kingdom="Animalia" order="Sabellida" pageId="16" pageNumber="1653" phylum="Annelida" rank="genus">
<emphasis box="[497,580,1417,1438]" italics="true" pageId="16" pageNumber="1653">Osedax</emphasis>
</taxonomicName>
has been found on fossil bones and teeth of Oligocene toothed and baleen-bearing mysticetes, including 
<collectingCountry box="[601,760,1478,1500]" name="New Zealand" pageId="16" pageNumber="1653">New Zealand</collectingCountry>
eomysticetids, odontocetes and marine birds (
<bibRefCitation author="Kiel S &amp; Goedert JL &amp; Kahl W &amp; Rouse GW" pageId="16" pageNumber="1653" pagination="8656 - 8659" refId="ref24963" refString="Kiel S, Goedert JL, Kahl W, Rouse GW. 2010. Fossil traces of the bone-eating worm Osedax in early Oligocene whale bones. Proceedings of the National Academy of Sciences 107: 8656 - 8659." type="journal article" year="2010">
Kiel 
<emphasis box="[145,191,1540,1561]" italics="true" pageId="16" pageNumber="1653">et al</emphasis>
., 2010
</bibRefCitation>
, 
<bibRefCitation author="Kiel S &amp; Kahl WA &amp; Goedert JL" box="[275,330,1540,1561]" pageId="16" pageNumber="1653" pagination="51 - 55" refId="ref25003" refString="Kiel S, Kahl WA, Goedert JL. 2011. Osedax borings in fossil marine bird bones. Naturwissenschaften 98: 51 - 55." type="journal article" year="2011">2011</bibRefCitation>
, 
<bibRefCitation author="Kiel S &amp; Kahl WA &amp; Goedert JL" box="[340,395,1540,1561]" pageId="16" pageNumber="1653" pagination="161 - 167" refId="ref25029" refString="Kiel S, Kahl WA, Goedert JL. 2013. Traces of the bone-eating annelid Osedax in Oligocene whale teeth and fish bones. Palaontologische Zeitschrift 87: 161 - 167." type="journal article" year="2013">2013</bibRefCitation>
; 
<bibRefCitation author="Higgs ND &amp; Little CTS &amp; Glover AG &amp; Dahlgren TG &amp; Smith CR &amp; Dominici S" box="[406,596,1540,1562]" pageId="16" pageNumber="1653" pagination="269 - 277" refId="ref24635" refString="Higgs ND, Little CTS, Glover AG, Dahlgren TG, Smith CR, Dominici S. 2012. Evidence of Osedax worm borings in Pliocene (~ 3 Ma) whale bone from the Mediterranean. Historical Biology 24: 269 - 277." type="journal article" year="2012">
Higgs 
<emphasis box="[477,531,1540,1561]" italics="true" pageId="16" pageNumber="1653">et al.</emphasis>
, 2012
</bibRefCitation>
; 
<bibRefCitation author="Boessenecker RW &amp; Fordyce RE" pageId="16" pageNumber="1653" pagination="107 - 140" refId="ref22372" refString="Boessenecker RW, Fordyce RE. 2015 a. A new eomysticetid (Mammalia: Cetacea) from the Late Oligocene of New Zealand and a re-evaluation of ' Mauicetus' waitakiensis. Papers in Paleontology 1: 107 - 140." type="journal article" year="2015">Boessenecker &amp; Fordyce, 2015a</bibRefCitation>
, d).
</paragraph>
<paragraph blockId="16.[145,762,926,1899]" lastBlockId="17.[163,780,197,1905]" lastPageId="17" lastPageNumber="1654" pageId="16" pageNumber="1653">
Six preserved double-rooted and two triple-rooted posterior cheek teeth are characterized by robust and moderately inflated crowns (
<figureCitation box="[471,540,1662,1684]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="16" pageNumber="1653">Figs 1</figureCitation>
, 
<figureCitation box="[553,567,1662,1683]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="16" pageNumber="1653">8</figureCitation>
). The crowns are elongate and compressed, with a triangular profile in labial and lingual views, similar to 
<taxonomicName box="[537,709,1724,1746]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
. The archaic toothed mysticete 
<taxonomicName authorityName="Mitchell" authorityYear="1989" box="[458,755,1754,1775]" class="Mammalia" family="Llanocetidae" genus="Llanocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="16" pageNumber="1653" phylum="Chordata" rank="species" species="denticrenatus">
<emphasis box="[458,755,1754,1775]" italics="true" pageId="16" pageNumber="1653">Llanocetus denticrenatus</emphasis>
</taxonomicName>
, from the latest Priabonian (latest Eocene) of 
<collectingCountry box="[145,267,1816,1838]" name="Antarctica" pageId="16" pageNumber="1653">Antarctica</collectingCountry>
, has posterior cheek teeth with crowns that are similarly compressed, as in 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[523,660,1847,1868]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[523,541,1847,1868]" italics="true" pageId="16" pageNumber="1653">K</emphasis>
. 
<emphasis box="[557,660,1847,1868]" italics="true" pageId="16" pageNumber="1653">onamata</emphasis>
</taxonomicName>
, but are lower and more elongate, resembling the deciduous teeth of 
<taxonomicName box="[903,1073,926,948]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
(
<bibRefCitation author="Kellogg AR" box="[1089,1243,926,948]" pageId="16" pageNumber="1653" pagination="1 - 366" refId="ref24941" refString="Kellogg AR. 1936. A review of the Archaeoceti. Carnegie Institute of Washington Publication 482: 1 - 366." type="journal article" year="1936">Kellogg, 1936</bibRefCitation>
; 
<bibRefCitation author="Mitchell ED" box="[1256,1419,926,948]" pageId="16" pageNumber="1653" pagination="2219 - 2235" refId="ref25867" refString="Mitchell ED. 1989. A new cetacean from the Late Eocene La Meseta Formation, Seymour Island, Antarctic Peninsula. Canadian Journal of Fisheries and Aquatic Sciences 46: 2219 - 2235." type="journal article" year="1989">Mitchell, 1989</bibRefCitation>
; 
<bibRefCitation author="Uhen MD" box="[809,946,957,979]" pageId="16" pageNumber="1653" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen, 2004</bibRefCitation>
; 
<bibRefCitation author="Fordyce RE &amp; Marx FG" box="[962,1230,957,979]" pageId="16" pageNumber="1653" pagination="1670 - 1676" refId="ref23930" refString="Fordyce RE, Marx FG. 2018. Gigantism precedes filter feeding in baleen whale evolution. Current Biology 28: 1670 - 1676. e 2." type="journal article" year="2018">Fordyce &amp; Marx, 2018</bibRefCitation>
). The crowns in 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[809,952,988,1009]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[809,827,988,1009]" italics="true" pageId="16" pageNumber="1653">K</emphasis>
. 
<emphasis box="[845,952,988,1009]" italics="true" pageId="16" pageNumber="1653">onamata</emphasis>
</taxonomicName>
are subvertically oriented. Presumed upper cheek teeth are differentiated by a prominent lingual concavity that is continuous through the root, forming a crescent-shape; the roots of presumed lower cheek teeth are subvertical and moderately concave lingually. An inferred right P3 (
<figureCitation box="[1294,1368,1141,1163]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="16" pageNumber="1653">Figs 1</figureCitation>
, 
<figureCitation box="[1384,1416,1141,1162]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="16" pageNumber="1653">8B</figureCitation>
) has the largest crown size in the upper tooth row. The crown of an inferred left P4 (
<figureCitation box="[1199,1270,1202,1224]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="16" pageNumber="1653">Figs 1</figureCitation>
, 
<figureCitation box="[1284,1317,1202,1223]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="16" pageNumber="1653">8D</figureCitation>
) is badly damaged but is proportionally smaller than P3. The preserved posterior-half of an inferred left M1 (
<figureCitation box="[1338,1416,1263,1285]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="16" pageNumber="1653">Fig. 8F</figureCitation>
) indicates that crown size in M1 was subequal to P4. The M1 is broken and longitudinally bisected slightly posterior to the anteroposterior midline, exposing an isthmus of cementum and dentin that extends below to the preserved apical-half of the posterior root. An inferred left P2 was figured by 
<bibRefCitation author="Hector J" box="[1270,1419,1448,1469]" pageId="16" pageNumber="1653" pagination="434 - 436" refId="ref24521" refString="Hector J. 1881. Notes on New Zealand Cetacea, recent and fossil. Transactions of the New Zealand Institute 13: 434 - 436." type="journal article" year="1881">Hector (1881</bibRefCitation>
: figs 4–4’), depicting a double-rooted tooth with a large, triangular crown in labial and lingual views (
<figureCitation box="[1345,1410,1509,1531]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="16" pageNumber="1653">Fig. 1</figureCitation>
). However, the whereabouts of the tooth are unknown. Based on the figure, crown size appears to be larger in P2 relative to P3, although the exact dimensions of the crown of P2 are unknown. In the basilosaurid 
<taxonomicName authorityName="Andrews" authorityYear="1906" class="Mammalia" family="Basilosauridae" genus="Dorudon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="species" species="atrox">
<emphasis italics="true" pageId="16" pageNumber="1653">Dorudon atrox</emphasis>
</taxonomicName>
, the crown of P2 is dimensionally largest in the upper-posterior cheek tooth series (
<bibRefCitation author="Uhen MD" box="[1207,1337,1693,1715]" pageId="16" pageNumber="1653" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen, 2004</bibRefCitation>
). In the lower tooth row of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[1032,1168,1724,1745]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[1032,1050,1724,1745]" italics="true" pageId="16" pageNumber="1653">K</emphasis>
. 
<emphasis box="[1065,1168,1724,1745]" italics="true" pageId="16" pageNumber="1653">onamata</emphasis>
</taxonomicName>
, crown size increases posteriorly through the lower premolar series, with p4 having the largest crown size (
<figureCitation box="[1221,1295,1785,1807]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="16" pageNumber="1653">
Figs 
<geoCoordinate box="[1281,1295,1785,1806]" degrees="1, 8" direction="east" orientation="longitude" pageId="16" pageNumber="1653" precision="5555" value="1.8">1</geoCoordinate>
</figureCitation>
, 
<figureCitation box="[1310,1342,1785,1806]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="16" pageNumber="1653">8E</figureCitation>
); p4 is the largest tooth in the lower posterior cheek tooth series in 
<taxonomicName authority="(Uhen, 2004)" baseAuthorityName="Uhen" baseAuthorityYear="2004" box="[910,1152,1846,1868]" class="Mammalia" family="Basilosauridae" genus="Dorudon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="16" pageNumber="1653" phylum="Chordata" rank="species" species="atrox">
<emphasis box="[910,929,1847,1868]" italics="true" pageId="16" pageNumber="1653">D</emphasis>
. 
<emphasis box="[941,999,1847,1868]" italics="true" pageId="16" pageNumber="1653">atrox</emphasis>
(
<bibRefCitation author="Uhen MD" box="[1013,1142,1846,1868]" pageId="16" pageNumber="1653" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen, 2004</bibRefCitation>
)
</taxonomicName>
. Crown width decreases between an inferred right p2 (
<figureCitation box="[1156,1227,1877,1899]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="16" pageNumber="1653">Figs 1</figureCitation>
, 
<figureCitation box="[1240,1271,1877,1898]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="16" pageNumber="1653">8A</figureCitation>
) and p3 (
<figureCitation captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" lastPageId="17" lastPageNumber="1654" pageId="16" pageNumber="1653">Fig. 8C</figureCitation>
), but is subequal between p3 and an inferred left p4 (
<figureCitation box="[205,274,228,250]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="17" pageNumber="1654">
Figs 
<geoCoordinate box="[260,274,228,249]" degrees="1, 8" direction="east" orientation="longitude" pageId="17" pageNumber="1654" precision="5555" value="1.8">1</geoCoordinate>
</figureCitation>
, 
<figureCitation box="[286,318,228,249]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="17" pageNumber="1654">8E</figureCitation>
). The crown of an inferred right m1 (
<figureCitation captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="17" pageNumber="1654">Fig. 8G</figureCitation>
) is more elongate and transversely wider than p4 and is slightly less tall, unlike 
<taxonomicName box="[525,699,289,311]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
where m1 is considerably smaller than the lower premolar series. An inferred right m2 (
<figureCitation box="[488,571,350,372]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="17" pageNumber="1654">Fig. 8H</figureCitation>
) is incomplete but is proportionally smaller than m1. The enamel on the labial and lingual surfaces of the posterior cheek teeth is weakly ornamented with a wrinkled texture that is confined to the basal-half to basal-third of the crown. Apically, the enamel is smooth. The ectocingulum and entocingulum are weakly developed thickened bands of smooth enamel on all posterior cheek teeth that preserve the basal crown around the enamel– cementum junction. Three distinct, ovoid, pit-like depressions are present on the labial surface of m2. The enamel is unworn within the depressions, indicating that they are not wear facets but are original structural features. All three depressions are located at different elevations on the crown: the first and most elevated depression is located approximately level to the preserved base of the accessory denticle immediately posteriorly adjacent to the primary denticle and is positioned on the approximate anteroposterior midline of the crown; the second depression is located 
<emphasis box="[690,707,934,955]" italics="true" pageId="17" pageNumber="1654">c.</emphasis>
<quantity box="[714,779,933,954]" metricMagnitude="-3" metricUnit="m" metricValue="3.0" pageId="17" pageNumber="1654" unit="mm" value="3.0">3 mm</quantity>
below the former and is similarly located on the anteroposterior midline; lastly, the third depression is located 
<emphasis box="[292,310,1026,1047]" italics="true" pageId="17" pageNumber="1654">c.</emphasis>
<quantity box="[321,390,1025,1047]" metricMagnitude="-3" metricUnit="m" metricValue="5.0" pageId="17" pageNumber="1654" unit="mm" value="5.0">5 mm</quantity>
below the second and 
<emphasis box="[681,698,1026,1047]" italics="true" pageId="17" pageNumber="1654">c.</emphasis>
<quantity box="[709,778,1025,1047]" metricMagnitude="-3" metricUnit="m" metricValue="6.0" pageId="17" pageNumber="1654" unit="mm" value="6.0">6 mm</quantity>
anterior to the anteroposterior midline of the crown and is more subrounded than the previous two. All depressions are similarly obliquely oriented relative to the vertical axis of the crown. Two hypotheses are proposed for the formation of the depressions: (1) the depressions are an indication of vertebrate scavenging (e.g. sharks; 
<bibRefCitation author="Demere TA &amp; Cerutti RA" box="[470,772,1240,1262]" pageId="17" pageNumber="1654" pagination="1480 - 1482" refId="ref23069" refString="Demere TA, Cerutti RA. 1982. A Pliocene shark attack on a cethotheriid whale. Journal of Paleontology 56: 1480 - 1482." type="journal article" year="1982">Deméré &amp; Cerutti, 1982</bibRefCitation>
; 
<bibRefCitation author="Boessenecker RW &amp; Fordyce RE" box="[163,518,1270,1292]" pageId="17" pageNumber="1654" pagination="326 - 331" refId="ref22519" refString="Boessenecker RW, Fordyce RE. 2015 d. Trace fossil evidence of predation upon bone-eating worms on a baleen whale skeleton from the Oligocene of New Zealand. Lethaia 48: 326 - 331." type="journal article" year="2015">Boessenecker &amp; Fordyce, 2015d</bibRefCitation>
); or (2) the depressions are congenital and represent a malformation of the enamel or ontogenetic damage that occurred early in tooth mineralization, assuming that 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[592,726,1363,1384]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[592,610,1363,1384]" italics="true" pageId="17" pageNumber="1654">K</emphasis>
. 
<emphasis box="[624,726,1363,1384]" italics="true" pageId="17" pageNumber="1654">onamata</emphasis>
</taxonomicName>
was diphyodont, before the pulp cavity of m2 was infilled. Regarding the former hypothesis, the morphology of the depressions differs from previously interpreted evidence of shark predation or scavenging from fossil whale bones, which are slit-like excavations (
<bibRefCitation author="Demere TA &amp; Cerutti RA" pageId="17" pageNumber="1654" pagination="1480 - 1482" refId="ref23069" refString="Demere TA, Cerutti RA. 1982. A Pliocene shark attack on a cethotheriid whale. Journal of Paleontology 56: 1480 - 1482." type="journal article" year="1982">Deméré &amp; Cerutti, 1982</bibRefCitation>
; 
<bibRefCitation author="Boessenecker RW &amp; Fordyce RE" box="[330,694,1546,1568]" pageId="17" pageNumber="1654" pagination="326 - 331" refId="ref22519" refString="Boessenecker RW, Fordyce RE. 2015 d. Trace fossil evidence of predation upon bone-eating worms on a baleen whale skeleton from the Oligocene of New Zealand. Lethaia 48: 326 - 331." type="journal article" year="2015">Boessenecker &amp; Fordyce, 2015d</bibRefCitation>
). Thus, the depressions are probably representative of enamel malformations rather than post-mortem predation by other marine vertebrates.
</paragraph>
<paragraph blockId="17.[163,780,197,1905]" lastBlockId="17.[827,1444,197,1905]" pageId="17" pageNumber="1654">
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[187,420,1669,1691]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[187,420,1669,1691]" italics="true" pageId="17" pageNumber="1654">Kekenodon onamata</emphasis>
</taxonomicName>
presents teeth with a vestigial third lingual root identified as the P3 (
<figureCitation box="[646,721,1700,1722]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="17" pageNumber="1654">Figs 1</figureCitation>
, 
<figureCitation box="[737,769,1700,1721]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="17" pageNumber="1654">8B</figureCitation>
) and P4 (
<figureCitation box="[261,332,1730,1752]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="17" pageNumber="1654">Figs 1</figureCitation>
, 
<figureCitation box="[345,378,1730,1751]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="17" pageNumber="1654">8D</figureCitation>
). In each, the lingual root is fused with the posterior root and is partially fused with the anterior root; a narrow and shallow sulcus separates the lingual and anterior roots and is continuous for the preserved length of P3 and P4. Basally, the lingual root closely approximates the anterior root but is not fused. It is not clear if the lingual and posterior roots become unfused at their distal extremity, similar to the squalodontid odontocete 
<taxonomicName authority="(Rothausen, 1968)" baseAuthorityName="Rothausen" baseAuthorityYear="1968" class="Mammalia" family="Squalodontidae" genus="Squalodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="catulli">
<emphasis box="[1221,1443,258,279]" italics="true" pageId="17" pageNumber="1654">Squalodon catulli</emphasis>
(
<bibRefCitation author="Rothausen K" box="[836,1038,289,311]" pageId="17" pageNumber="1654" pagination="83 - 104" refId="ref26225" refString="Rothausen K. 1968. Die systematische Stellung der europaischen Squalodontidae (Odontoceti, Mamm.). Palaontoloische Zeitschrift 42: 83 - 104." type="journal article" year="1968">Rothausen, 1968</bibRefCitation>
)
</taxonomicName>
; unfused triple-rooted teeth are absent in 
<taxonomicName box="[947,1125,319,341]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
but are known from early Middle Eocene 
<taxonomicName box="[1016,1169,350,372]" class="Mammalia" family="Protocetidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="family">Protocetidae</taxonomicName>
(
<bibRefCitation author="Bajpai S &amp; Thewissen JGM" pageId="17" pageNumber="1654" pagination="213 - 233" refId="ref22216" refString="Bajpai S, Thewissen JGM. 1998. Middle Eocene cetaceans from the Harudi and Subathu formations of India. In: Thewissen JGM, ed. The emergence of whales. New York: Plenum Press, 213 - 233." type="book chapter" year="1998">Bajpai &amp; Thewissen, 1998</bibRefCitation>
; 
<bibRefCitation author="Hulbert RC Jr &amp; Petkewich RM &amp; Bishop GA &amp; Bukry D &amp; Aleshire DP" box="[895,1116,381,403]" pageId="17" pageNumber="1654" pagination="907 - 927" refId="ref24734" refString="Hulbert RC Jr, Petkewich RM, Bishop GA, Bukry D, Aleshire DP. 1998. A new middle Eocene protocetid whale (Mammalia: Cetacea: Archaeoceti) and associated biota from Georgia. Journal of Paleontology 72: 907 - 927." type="journal article" year="1998">
Hulbert 
<emphasis box="[992,1048,381,402]" italics="true" pageId="17" pageNumber="1654">et al.</emphasis>
, 1998
</bibRefCitation>
). The posterolingual surface of the crown of P3 and P4 is inflated, forming a bulge in the cervical region of the crown. A lingual bulge is present in semi-amphibious heterodont archaeocetes and has been interpreted as a protocone remnant (
<bibRefCitation author="Gingerich PD &amp; Russell DE" box="[949,1269,534,556]" pageId="17" pageNumber="1654" pagination="1 - 20" refId="ref24301" refString="Gingerich PD, Russell DE. 1990. Dentition of early Eocene Pakicetus (Mammalia, Cetacea). Contributions from the Museum of Paleontology University of Michigan 28: 1 - 20." type="journal article" year="1990">Gingerich &amp; Russell, 1990</bibRefCitation>
; 
<bibRefCitation author="Thewissen JGM &amp; Bajpai S" pageId="17" pageNumber="1654" pagination="463 - 465" refId="ref26601" refString="Thewissen JGM, Bajpai S. 2001. Dental morphology of Remingtonocetidae (Cetacea, Mammalia). Journal of Paleontology 75: 463 - 465." type="journal article" year="2001">Thewissen &amp; Bajpai, 2001</bibRefCitation>
; 
<bibRefCitation author="Gingerich PD" box="[985,1167,565,587]" pageId="17" pageNumber="1654" pagination="873 - 899" refId="ref24230" refString="Gingerich PD. 2010. Cetacea. In: Werdelin L, Sanders WJ, eds. Cenozoic Mammals of Africa. Berkeley: University of California Press, 873 - 899." type="book chapter" year="2010">Gingerich, 2010</bibRefCitation>
; 
<bibRefCitation author="Gingerich PD &amp; Cappetta H" pageId="17" pageNumber="1654" pagination="109 - 129" refId="ref24263" refString="Gingerich PD, Cappetta H. 2014. A new archaeocete and other marine mammals (Cetacea and Sirenia) from lower middle Eocene phosphate deposits of Togo. Journal of Paleontology 88: 109 - 129." type="journal article" year="2014">Gingerich &amp; Cappetta, 2014</bibRefCitation>
). In toothed mysticetes, the mammalodontids 
<taxonomicName authorityName="Pritchard" authorityYear="1939" box="[827,1119,626,647]" class="Mammalia" family="Squalodontidae" genus="Mammalodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="colliveri">
<emphasis box="[827,1119,626,647]" italics="true" pageId="17" pageNumber="1654">Mammalodon colliveri</emphasis>
</taxonomicName>
and 
<taxonomicName authorityName="Fitzgerald" authorityYear="2006" box="[1191,1443,626,648]" class="Mammalia" family="Mammalodontidae" genus="Janjucetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="hunderi">
<emphasis box="[1191,1443,626,648]" italics="true" pageId="17" pageNumber="1654">Janjucetus hunderi</emphasis>
</taxonomicName>
present postcanine teeth that are lingually inflated, which could represent a vestigial third root, whereas all double-rooted teeth of the toothed mysticete 
<taxonomicName box="[827,1095,749,770]" class="Mammalia" genus="Coronodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="havensteini">
<emphasis box="[827,1095,749,770]" italics="true" pageId="17" pageNumber="1654">Coronodon havensteini</emphasis>
</taxonomicName>
have a small ‘demi-root’ that becomes unfused near its basal extremity and forms a noticeable projection. Elsewhere, 
<taxonomicName authority="Molin, 1859" authorityName="Molin" authorityYear="1859" class="Mammalia" genus="Trirhizodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="genus">
<emphasis box="[1292,1443,810,831]" italics="true" pageId="17" pageNumber="1654">Trirhizodon</emphasis>
<bibRefCitation author="Molin DR" box="[827,978,841,863]" pageId="17" pageNumber="1654" pagination="117 - 128" refId="ref25902" refString="Molin DR. 1859. Sulle reliquie d'un Pachyodon disoterrate a Libano due ore Nord-Est di Belluno in mezzo all'arenaria grigia. Kaiserlich Akademie der wissenschaften in Wien, Sitzungsberichte Mathematisch-naturwissenschaftliche Klasse 35: 117 - 128." type="journal article" year="1859">Molin, 1859</bibRefCitation>
</taxonomicName>
and 
<taxonomicName authority="Climo &amp; Baker, 1972" authorityName="Climo &amp; Baker" authorityYear="1972" class="Mammalia" family="Squalodelphidae" genus="Austrosqualodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="trirhizodonta">
<emphasis box="[1048,1442,841,862]" italics="true" pageId="17" pageNumber="1654">Austrosqualodon trirhizodonta</emphasis>
Climo &amp; Baker, 1972
</taxonomicName>
, both previously referred to 
<taxonomicName authorityName="Brandt" authorityYear="1873" box="[827,1011,902,924]" class="Mammalia" family="Squalodontidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="family">Squalodontidae</taxonomicName>
, have triple-rooted molariform teeth with the basal two-thirds of the lingual root not fused to the anterior and posterior roots (
<bibRefCitation author="Molin DR" box="[1302,1436,963,985]" pageId="17" pageNumber="1654" pagination="117 - 128" refId="ref25902" refString="Molin DR. 1859. Sulle reliquie d'un Pachyodon disoterrate a Libano due ore Nord-Est di Belluno in mezzo all'arenaria grigia. Kaiserlich Akademie der wissenschaften in Wien, Sitzungsberichte Mathematisch-naturwissenschaftliche Klasse 35: 117 - 128." type="journal article" year="1859">Molin, 1859</bibRefCitation>
; 
<bibRefCitation author="Kellogg AR" box="[827,981,994,1016]" pageId="17" pageNumber="1654" pagination="1 - 69" refId="ref24870" refString="Kellogg AR. 1923. Description of two squalodonts recently discovered in the Calvert Cliffs, Maryland; and notes on the shark-toothed dolphins. Proceedings of the United States National Museum 62: 1 - 69." type="journal article" year="1923">Kellogg, 1923</bibRefCitation>
; 
<bibRefCitation author="Rothausen K" box="[994,1186,994,1016]" pageId="17" pageNumber="1654" pagination="83 - 104" refId="ref26225" refString="Rothausen K. 1968. Die systematische Stellung der europaischen Squalodontidae (Odontoceti, Mamm.). Palaontoloische Zeitschrift 42: 83 - 104." type="journal article" year="1968">Rothausen, 1968</bibRefCitation>
).
</paragraph>
<paragraph blockId="17.[827,1444,197,1905]" lastBlockId="18.[145,762,197,1905]" lastPageId="18" lastPageNumber="1655" pageId="17" pageNumber="1654">
All crowns of the posterior cheek teeth are denticulate. The accessory denticles are robust, unlike the comparatively gracile denticles of archaic heterodont Odontoceti (
<bibRefCitation author="Kellogg AR" box="[1104,1262,1117,1139]" pageId="17" pageNumber="1654" pagination="1 - 69" refId="ref24870" refString="Kellogg AR. 1923. Description of two squalodonts recently discovered in the Calvert Cliffs, Maryland; and notes on the shark-toothed dolphins. Proceedings of the United States National Museum 62: 1 - 69." type="journal article" year="1923">Kellogg, 1923</bibRefCitation>
; 
<bibRefCitation author="Fordyce RE" box="[1276,1437,1117,1139]" pageId="17" pageNumber="1654" pagination="1028 - 1045" refId="ref23517" refString="Fordyce RE. 1981. Systematics of the odontocete whale Agorophius pygmaeus and the family Agorophiidae (Mammalia: Cetacea). Journal of Paleontology 55: 1028 - 1045." type="journal article" year="1981">Fordyce, 1981</bibRefCitation>
, 
<bibRefCitation author="Fordyce RE" box="[827,882,1147,1168]" pageId="17" pageNumber="1654" pagination="147 - 176" refId="ref23644" refString="Fordyce RE. 1994. Waipatia maerewhenua, a new genus and new species (Waipatiidae, new Family), an archaic Late Oligocene dolphin (Cetacea: Odontoceti: Platanistoidea) from New Zealand. In: Berta A, Demere TA, eds. Contributions in marine mammal paleontology honoring Frank C. Whitmore, Jr. Proceedings of the San Diego Society of Natural History 29: 147 - 176." type="journal article" year="1994">1994</bibRefCitation>
, 
<bibRefCitation author="Fordyce RE" box="[896,965,1147,1169]" pageId="17" pageNumber="1654" pagination="185 - 222" refId="ref23756" refString="Fordyce RE. 2002 b. Simocetus rayi (Odontoceti: Simocetidae, new family): a bizarre new archaic Oligocene dolphin from the eastern North Pacific. Smithsonian Contributions to Paleobiology 93: 185 - 222." type="journal article" year="2002">2002b</bibRefCitation>
; 
<bibRefCitation author="Dubrovo IA &amp; Sanders AE" box="[979,1275,1147,1169]" pageId="17" pageNumber="1654" pagination="577 - 590" refId="ref23095" refString="Dubrovo IA, Sanders AE. 2000. A new species of Patriocetus (Mammalia, Cetacea) from the late Oligocene of Kazakhstan. Journal of Vertebrate Paleontology 20: 577 - 590." type="journal article" year="2000">Dubrovo &amp; Sanders, 2000</bibRefCitation>
; 
<bibRefCitation author="Geisler JH &amp; Colbert MW &amp; Carew JL" pageId="17" pageNumber="1654" pagination="383 - 386" refId="ref24166" refString="Geisler JH, Colbert MW, Carew JL. 2014. A new fossil species supports an early origin for toothed whale echolocation. Nature 508: 383 - 386." type="journal article" year="2014">
Geisler 
<emphasis box="[1379,1437,1147,1169]" italics="true" pageId="17" pageNumber="1654">et al.</emphasis>
, 2014
</bibRefCitation>
; 
<bibRefCitation author="Tanaka Y &amp; Fordyce RE" box="[896,1179,1178,1200]" pageId="17" pageNumber="1654" pagination="107972" refId="ref26389" refString="Tanaka Y, Fordyce RE. 2014. Fossil dolphin Otekaikea marplesi (Latest Oligocene, New Zealand) expands the morphological and taxonomic diversity of Oligocene cetaceans. PLoS One 9: e 107972." type="journal article" year="2014">Tanaka &amp; Fordyce, 2014</bibRefCitation>
, 
<bibRefCitation author="Tanaka Y &amp; Fordyce RE" box="[1193,1262,1178,1200]" pageId="17" pageNumber="1654" pagination="135 - 150" refId="ref26425" refString="Tanaka Y, Fordyce RE. 2015 a. Historically significant Late Oligocene dolphin Microcetus hectori Benham 1935: a new species of Waipatia (Platanistoidea). Journal of the Royal Society of New Zealand 45: 135 - 150." type="journal article" year="2015">2015a</bibRefCitation>
), in addition to mammalodontid and aetiocetid toothed mysticetes (
<bibRefCitation author="Emlong D" box="[836,1004,1239,1261]" pageId="17" pageNumber="1654" pagination="1 - 51" refId="ref23130" refString="Emlong D. 1966. A new archaic cetacean from the Oligocene of Northwest Oregon. Bulletin of the Museum of Natural History, University of Oregon 3: 1 - 51." type="journal article" year="1966">Emlong, 1966</bibRefCitation>
; 
<bibRefCitation author="Fitzgerald EMG" box="[1022,1224,1239,1261]" pageId="17" pageNumber="1654" pagination="2955 - 2963" refId="ref23347" refString="Fitzgerald EMG. 2006. A bizarre new toothed mysticete (Cetacea) from Australia and the early evolution of baleen whales. Proceedings of the Royal Society B: Biological Sciences 273: 2955 - 2963." type="journal article" year="2006">Fitzgerald, 2006</bibRefCitation>
, 
<bibRefCitation author="Fitzgerald EMG" box="[1242,1300,1239,1260]" pageId="17" pageNumber="1654" pagination="367 - 476" refId="ref23385" refString="Fitzgerald EMG. 2010. The morphology and systematics of Mammalodon colliveri (Cetacea: Mysticeti), a toothed mysticete from the Oligocene of Australia. Zoological Journal of the Linnean Society 158: 367 - 476." type="journal article" year="2010">2010</bibRefCitation>
; 
<bibRefCitation author="Demere TA &amp; Berta A" pageId="17" pageNumber="1654" pagination="308 - 352" refId="ref23026" refString="Demere TA, Berta A. 2008. Skull anatomy of the Oligocene toothed mysticete Aetiocetus weltoni (Mammalia; Cetacea): implications for mysticete evolution and functional anatomy. Zoological Journal of the Linnean Society 154: 308 - 352." type="journal article" year="2008">Deméré &amp; Berta, 2008</bibRefCitation>
; Marx 
<emphasis box="[1037,1092,1270,1292]" italics="true" pageId="17" pageNumber="1654">et al.</emphasis>
, 2015). The accessory denticles have a triangular profile in labial and lingual views, with subvertical axes. A moderately deep V-shaped gap separates all accessory denticles, as in 
<taxonomicName box="[1272,1442,1362,1384]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
and 
<taxonomicName authority="(Geisler et al., 2017)" baseAuthorityName="Geisler" baseAuthorityYear="2017" box="[879,1404,1393,1415]" class="Mammalia" genus="Coronodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="havensteini">
<emphasis box="[879,1151,1393,1414]" italics="true" pageId="17" pageNumber="1654">Coronodon havensteini</emphasis>
(
<bibRefCitation author="Geisler JH &amp; Boessenecker RW &amp; Brown M &amp; Beatty BL" box="[1169,1393,1393,1415]" pageId="17" pageNumber="1654" pagination="20361 - 2042" refId="ref24197" refString="Geisler JH, Boessenecker RW, Brown M, Beatty BL. 2017. The origin of filter feeding in whales. Current Biology 27: 20361 - 2042. e 2." type="journal article" year="2017">
Geisler 
<emphasis box="[1262,1322,1393,1414]" italics="true" pageId="17" pageNumber="1654">et al.</emphasis>
, 2017
</bibRefCitation>
)
</taxonomicName>
. In 
<taxonomicName authorityName="Mitchell" authorityYear="1989" box="[827,1118,1423,1444]" class="Mammalia" family="Llanocetidae" genus="Llanocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="denticrenatus">
<emphasis box="[827,1118,1423,1444]" italics="true" pageId="17" pageNumber="1654">Llanocetus denticrenatus</emphasis>
</taxonomicName>
, the accessory denticles are noticeably more palmate and are concave toward the primary denticle, producing less subvertical axes than in 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[853,1080,1515,1537]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="17" pageNumber="1654" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[853,1080,1515,1537]" italics="true" pageId="17" pageNumber="1654">Kekenodon onamata</emphasis>
</taxonomicName>
(
<bibRefCitation author="Mitchell ED" box="[1092,1251,1515,1537]" pageId="17" pageNumber="1654" pagination="2219 - 2235" refId="ref25867" refString="Mitchell ED. 1989. A new cetacean from the Late Eocene La Meseta Formation, Seymour Island, Antarctic Peninsula. Canadian Journal of Fisheries and Aquatic Sciences 46: 2219 - 2235." type="journal article" year="1989">Mitchell, 1989</bibRefCitation>
; 
<bibRefCitation author="Fordyce RE &amp; Marx FG" pageId="17" pageNumber="1654" pagination="1670 - 1676" refId="ref23930" refString="Fordyce RE, Marx FG. 2018. Gigantism precedes filter feeding in baleen whale evolution. Current Biology 28: 1670 - 1676. e 2." type="journal article" year="2018">Fordyce &amp; Marx, 2018</bibRefCitation>
). A narrow and shallow sulcus is continuous with the apex of the 
<collectionCode box="[1003,1021,1577,1598]" country="Canada" lsid="urn:lsid:biocol.org:col:13946" name="Royal British Columbia Museum - Herbarium" pageId="17" pageNumber="1654" type="Museum">V</collectionCode>
and extends basally down the crown on the labial and lingual surfaces, forming a boundary between adjacent denticles. Anterior and posterior carinae are present on all preserved denticles. The primary denticle is distinctly larger than all accessory denticles. In general, approximately one additional denticle is present on the posterior surface of the crown than on the anterior surface, although P3 has an equal number of anterior and posterior accessory denticles (
<emphasis box="[835,855,1853,1874]" italics="true" pageId="17" pageNumber="1654">N</emphasis>
= 4). Additionally, P4 may have an equal number of anterior and posterior accessory denticles. However, the number of anterior accessory denticles is uncertain. In occlusal view, the accessory and primary denticles of p3 (
<figureCitation box="[220,306,258,280]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8C</figureCitation>
) and p4 (
<figureCitation box="[422,495,258,280]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="18" pageNumber="1655">
Figs 
<geoCoordinate box="[481,495,259,280]" degrees="1, 8" direction="east" orientation="longitude" pageId="18" pageNumber="1655" precision="5555" value="1.8">1</geoCoordinate>
</figureCitation>
, 
<figureCitation box="[510,542,259,280]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">8E</figureCitation>
) have a sigmoidal alignment anteroposteriorly. Accessory denticles are present on the anterior surface of an inferred m1 (
<figureCitation captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8G</figureCitation>
) and m2 (
<figureCitation box="[303,391,350,372]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8H</figureCitation>
), whereas the anterior surface of the lower molars in basilosaurids is occupied by a re-entrant groove to accommodate the posterior edge of the preceding tooth in the upper tooth row (
<bibRefCitation author="Uhen MD" pageId="18" pageNumber="1655" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen, 2004</bibRefCitation>
); there is no evidence of a re-entrant groove in 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[145,282,504,525]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="18" pageNumber="1655" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[145,163,504,525]" italics="true" pageId="18" pageNumber="1655">K</emphasis>
. 
<emphasis box="[178,282,504,525]" italics="true" pageId="18" pageNumber="1655">onamata</emphasis>
</taxonomicName>
. Within Neoceti, the anterior surface of the m3 crown in the Oligocene odontocete 
<taxonomicName authority="Fordyce, 2002" authorityName="Fordyce" authorityYear="2002" class="Mammalia" family="Simocetidae" genus="Simocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="18" pageNumber="1655" phylum="Chordata" rank="species" species="rayi">
<emphasis italics="true" pageId="18" pageNumber="1655">Simocetus rayi</emphasis>
Fordyce, 2002
</taxonomicName>
lacks accessory denticles and consists of a planar face with bilateral ridges forming the buccal and lingual margins, possibly representing a re-entrant groove (
<bibRefCitation author="Fordyce RE" box="[392,569,657,679]" pageId="18" pageNumber="1655" pagination="185 - 222" refId="ref23756" refString="Fordyce RE. 2002 b. Simocetus rayi (Odontoceti: Simocetidae, new family): a bizarre new archaic Oligocene dolphin from the eastern North Pacific. Smithsonian Contributions to Paleobiology 93: 185 - 222." type="journal article" year="2002">Fordyce, 2002b</bibRefCitation>
). The preserved posterior-half of the left M1 (
<figureCitation box="[491,575,688,710]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8F</figureCitation>
) preserves four accessory denticles, in addition to the posterior-third of the primary denticle. The number of accessory denticles on the anterior surface is speculative, while there are four posterior accessory denticles. As in 
<taxonomicName authority="(Uhen, 2004)" baseAuthorityName="Uhen" baseAuthorityYear="2004" box="[145,486,841,863]" class="Mammalia" family="Basilosauridae" genus="Dorudon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="18" pageNumber="1655" phylum="Chordata" rank="species" species="atrox">
<emphasis box="[145,319,841,863]" italics="true" pageId="18" pageNumber="1655">Dorudon atrox</emphasis>
(
<bibRefCitation author="Uhen MD" box="[338,476,841,863]" pageId="18" pageNumber="1655" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen, 2004</bibRefCitation>
)
</taxonomicName>
, it is possible that the number of anterior and posterior accessory denticles on the M1 of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[294,425,903,924]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="18" pageNumber="1655" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[294,312,903,924]" italics="true" pageId="18" pageNumber="1655">K</emphasis>
. 
<emphasis box="[325,425,903,924]" italics="true" pageId="18" pageNumber="1655">onamata</emphasis>
</taxonomicName>
were equal.
</paragraph>
<paragraph blockId="18.[145,762,197,1905]" lastBlockId="18.[809,1426,197,1905]" pageId="18" pageNumber="1655">
Subhorizontal abrasional apical wear facets are prevalent on nearly all preserved denticles of the posterior cheek teeth. Moreover, most have been severely worn down to the denticle base. Vertically oriented, teardrop-shaped, attritional wear facets are evident on the lingual surface of provisionally identified upper-posterior cheek teeth (
<figureCitation box="[468,603,1117,1139]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8B, D, F</figureCitation>
). The absence of attritional facets from the labial surface of these teeth probably indicates that the upper teeth were positioned labial to the lower teeth during occlusion, as in basilosaurids (
<bibRefCitation author="Uhen MD" box="[341,472,1240,1262]" pageId="18" pageNumber="1655" pagination="1 - 222" refId="ref26760" refString="Uhen MD. 2004. Form, function, and anatomy of Dorudon atrox (Mammalia, Cetacea): an archaeocete from the Middle to Late Eocene of Egypt. University of Michigan Papers on Paleontology 34: 1 - 222." type="journal article" year="2004">Uhen, 2004</bibRefCitation>
). The presence of enamel wear facets of similar profile on the lingual surface of provisionally identified p2 (
<figureCitation box="[509,595,1301,1323]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8A</figureCitation>
), p3 (
<figureCitation box="[666,752,1301,1323]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8C</figureCitation>
) and m1 (
<figureCitation box="[248,332,1332,1354]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8G</figureCitation>
) could represent abrasive wear from hard food particles. Alternatively, the facets may be attritional and indicate a large range of lateral motion. However, this is only speculative given the absence of preserved mandibles and crania. It is also possible that these teeth represent upper teeth, although the vertical orientation of the roots suggests a lower toothrow position. Two relatively large and longitudinal ovoid sections of missing enamel are located along the cervical region on the labial surface of the crown of p3 (
<figureCitation box="[153,234,1638,1660]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8C</figureCitation>
). The sections extend apically on to the crown and on to the root where they terminate at midlength; the enamel and underlying dentin have been removed. The more anterior section on p3 extends slightly further basally relative to the more posterior lesion. Both probably represent attritional wear that marks the extent of emergence from the gingiva. Alternatively, these sections could represent abfraction lesions (from Grippo, 1991) previously associated with crown flexure due to large stress loads (
<bibRefCitation author="McCoy G" box="[1112,1259,197,218]" pageId="18" pageNumber="1655" pagination="361 - 362" refId="ref25393" refString="McCoy G. 1982. The etiology of gingival erosion. Journal of Oral Implantology 10: 361 - 362." type="journal article" year="1982">McCoy, 1982</bibRefCitation>
; 
<bibRefCitation author="Lee WC &amp; Eakle WS" pageId="18" pageNumber="1655" pagination="374 - 380" refId="ref25220" refString="Lee WC, Eakle WS. 1984. Possible role of tensile stress in the etiology of cervical erosive lesions of teeth. Journal of Prosthetic Dentistry 52: 374 - 380." type="journal article" year="1984">Lee &amp; Eakle, 1984</bibRefCitation>
) and stress corrosion (
<bibRefCitation author="Grippo JO &amp; Masai JV" box="[1121,1370,227,249]" pageId="18" pageNumber="1655" pagination="71 - 76" refId="ref24419" refString="Grippo JO, Masai JV. 1991. Role of biodental engineering factors (BEF) in the etiology of root caries. Journal of Esthetic Dentistry 3: 71 - 76." type="journal article" year="1991">Grippo &amp; Masai, 1991</bibRefCitation>
). On the labial surface of the crown of P4 (
<figureCitation box="[1237,1320,258,280]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8D</figureCitation>
), most of the enamel on the preserved anterior-half of the crown has been spalled, creating a large window to expose the underlying dentin. Moreover, nearly all of the enamel on the labial surface of p4 has been spalled; a section of spalled enamel is present on the labiolingual surface of m1 on the cervical region of the crown.
</paragraph>
<paragraph blockId="18.[809,1426,197,1905]" lastBlockId="19.[163,780,197,1568]" lastPageId="19" lastPageNumber="1656" pageId="18" pageNumber="1655">
Associated roots of the double-rooted teeth are more vertically oriented than the recurved roots of the single-rooted teeth. The surfaces of the roots are convex, excluding the planar to slightly concave internal surfaces of the anterior and posterior roots. The anterior and posterior roots are fused or closely appressed, similar to mammalodontids, but unlike the widely spaced roots of 
<taxonomicName box="[1149,1334,687,709]" class="Mammalia" family="Basilosauridae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="18" pageNumber="1655" phylum="Chordata" rank="family">Basilosauridae</taxonomicName>
and 
<taxonomicName authorityName="Mitchell" authorityYear="1989" class="Mammalia" family="Llanocetidae" genus="Llanocetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Artiodactyla" pageId="18" pageNumber="1655" phylum="Chordata" rank="species" species="denticrenatus">
<emphasis box="[1401,1417,688,709]" italics="true" pageId="18" pageNumber="1655">L</emphasis>
. 
<emphasis box="[809,980,718,739]" italics="true" pageId="18" pageNumber="1655">denticrenatus</emphasis>
</taxonomicName>
, which form an ovoid to teardropshaped cleft that extends apically on to the cervical region of the crown, forming a U-shaped enamel– cementum junction (
<bibRefCitation author="Mitchell ED" box="[1049,1216,810,832]" pageId="18" pageNumber="1655" pagination="2219 - 2235" refId="ref25867" refString="Mitchell ED. 1989. A new cetacean from the Late Eocene La Meseta Formation, Seymour Island, Antarctic Peninsula. Canadian Journal of Fisheries and Aquatic Sciences 46: 2219 - 2235." type="journal article" year="1989">Mitchell, 1989</bibRefCitation>
; 
<bibRefCitation author="Fordyce RE &amp; Marx FG" pageId="18" pageNumber="1655" pagination="1670 - 1676" refId="ref23930" refString="Fordyce RE, Marx FG. 2018. Gigantism precedes filter feeding in baleen whale evolution. Current Biology 28: 1670 - 1676. e 2." type="journal article" year="2018">Fordyce &amp; Marx, 2018</bibRefCitation>
). In p2 (
<figureCitation box="[961,1031,841,863]" captionStart="Figure 1" captionStartId="1.[163,245,929,951]" captionTargetBox="[165,1444,198,887]" captionTargetId="figure-498@1.[163,1446,195,889]" captionTargetPageId="1" captionText="Figure 1. Lithograph of the material collected by Alexander McKay in November 1880 comprising the holotype of Kekenodon onamata (NMNZ Ma 306). Image reproduced from Hector (1881)." figureDoi="http://doi.org/10.5281/zenodo.7381114" httpUri="https://zenodo.org/record/7381114/files/figure.png" pageId="18" pageNumber="1655">Figs 1</figureCitation>
, 
<figureCitation box="[1044,1075,841,862]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">8A</figureCitation>
) and p3 (
<figureCitation box="[1184,1266,841,863]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8C</figureCitation>
), the anterior and posterior roots are subvertical, elongate, robust and inflated; the posterior root is proportionally more robust. The anterior and posterior roots have a subrounded cross-section that is greatest in diameter at midlength. From this location, the diameter of the root decreases slightly apically and more prominently basally. Fusion of anterior and posterior roots extends to midlength in p2 and the approximate preserved length in p3. A narrow and moderately deep sulcus forms along the fusion of the anterior and posterior roots on the lingual and labial surfaces; the sulcus is deeper on the labial surface. Basally, the anterior and posterior roots bifurcate, forming a V-shaped gap; the apex of the 
<collectionCode box="[1045,1063,1270,1291]" country="Canada" lsid="urn:lsid:biocol.org:col:13946" name="Royal British Columbia Museum - Herbarium" pageId="18" pageNumber="1655" type="Museum">V</collectionCode>
extends further apically in p2. The position of cementum bands near the midlength of the anterior and posterior roots, corresponding to the alveolar rim, in all preserved double-rooted posterior cheek teeth indicates that the teeth were moderately emergent. The location of cementum bands becomes increasingly more apical on the anterior and posterior roots of the posteriormost cheek, indicating that the upper and lower posteriormost cheek teeth were comparatively less emergent. Attritional wear facets extend basally to the approximate level of the cementum bands on the labial surface of p2, p3 and m1 (
<figureCitation box="[858,997,1638,1660]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8A, C, G</figureCitation>
), further indicating that the posterior cheek teeth were probably only moderately emergent. The exposed internal surface of the posterior-half of the crown and root of M1 (
<figureCitation box="[1106,1184,1730,1752]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="18" pageNumber="1655">Fig. 8F</figureCitation>
) reveals a triangular projection of dentin and pulp cavity, which is difficult to differentiate due to the missing anterior portion of M1 and the high level of mineralization; the projection basally extends 
<emphasis box="[990,1007,1853,1874]" italics="true" pageId="18" pageNumber="1655">c.</emphasis>
<quantity box="[1012,1089,1853,1874]" metricMagnitude="-2" metricUnit="m" metricValue="3.3" pageId="18" pageNumber="1655" unit="mm" value="33.0">33 mm</quantity>
and 
<quantity box="[1143,1220,1853,1874]" metricMagnitude="-2" metricUnit="m" metricValue="2.8" pageId="18" pageNumber="1655" unit="mm" value="28.0">28 mm</quantity>
from the enamel– cementum junction on the labial and lingual surfaces, respectively. This basally projecting isthmus probably acted as a buttress for the crown to accommodate large occlusal stress loads.
</paragraph>
<paragraph blockId="19.[163,780,197,1568]" pageId="19" pageNumber="1656">
<bibRefCitation author="Kellogg AR" box="[187,360,289,311]" pageId="19" pageNumber="1656" pagination="1 - 366" refId="ref24941" refString="Kellogg AR. 1936. A review of the Archaeoceti. Carnegie Institute of Washington Publication 482: 1 - 366." type="journal article" year="1936">Kellogg (1936)</bibRefCitation>
and 
<bibRefCitation author="Abel O" box="[421,558,289,311]" pageId="19" pageNumber="1656" pagination="155 - 224" refId="ref22037" refString="Abel O. 1914. Die Vorfahren der Bartaenwale. Denkschriften der KaiserlichenAkademie derWissenschaften MathematischNaturwissenschaftliche Klasse 90: 155 - 224." type="journal article" year="1914">Abel (1914)</bibRefCitation>
noted similarities between the p3 of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[403,549,320,341]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[403,421,320,341]" italics="true" pageId="19" pageNumber="1656">K</emphasis>
. 
<emphasis box="[440,549,320,341]" italics="true" pageId="19" pageNumber="1656">onamata</emphasis>
</taxonomicName>
(
<figureCitation box="[569,661,320,342]" captionStart="Figure 8" captionStartId="15.[163,241,1376,1398]" captionTargetBox="[165,1437,198,1331]" captionTargetId="figure-229@15.[163,1443,195,1336]" captionTargetPageId="15" captionText="Figure 8. Double-rooted teeth of Kekenodon onamata (NMNZ Ma 306) in labial (left) and lingual (right) view. A, presumed right p2. B, presumed right P3. C, presumed right p3. D, presumed left P4. E, presumed left p4. F, presumed left M1. G, presumed right m1. H, partial crown of lower postcanine – possibly right m2. Solid lines indicate crown inflation. Dotted lines indicate attritional and abrasional tooth wear." figureDoi="http://doi.org/10.5281/zenodo.7381130" httpUri="https://zenodo.org/record/7381130/files/figure.png" pageId="19" pageNumber="1656">Fig. 8C</figureCitation>
) and the taxonomically ambiguous 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[503,778,350,372]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[503,778,350,372]" italics="true" pageId="19" pageNumber="1656">Phococetus vasconum</emphasis>
</taxonomicName>
from the Burdigalian of 
<collectingCountry box="[471,556,382,403]" name="France" pageId="19" pageNumber="1656">France</collectingCountry>
(
<bibRefCitation author="Delfortrie E" box="[575,772,381,403]" pageId="19" pageNumber="1656" pagination="113 - 117" refId="ref22995" refString="Delfortrie E. 1873. Un Zeuglodon dans les faluns du sudouest de la France. Actes de la Societe Linneene de Bordeaux Series 3 9: 113 - 117." type="journal article" year="1873">Delfortrie, 1873</bibRefCitation>
; 
<bibRefCitation author="Kellogg AR" box="[163,324,412,434]" pageId="19" pageNumber="1656" pagination="1 - 366" refId="ref24941" refString="Kellogg AR. 1936. A review of the Archaeoceti. Carnegie Institute of Washington Publication 482: 1 - 366." type="journal article" year="1936">Kellogg, 1936</bibRefCitation>
; 
<bibRefCitation author="Uhen MD" box="[339,490,412,434]" pageId="19" pageNumber="1656" pagination="433 - 452" refId="ref26859" refString="Uhen MD. 2008 b. A new Xenorophus - like odontocete cetacean from the Oligocene of North Carolina and a discussion of the basal odontocete radiation. Journal of Systematic Palaeontology 6: 433 - 452." type="journal article" year="2008">Uhen, 2008b</bibRefCitation>
), including the size and shape of the crown, lack of prominent cingulum in the cervical region of the crown, enamel ornamented with longitudinal ridges around the base of the crown on the labial and lingual surfaces, smooth enamel on the accessory denticles, the number and arrangement of the accessory denticles, the decrease of accessory denticle size towards the base of the crown, the lowlying and transversely compressed dimensions of the crown, the teeth are double-rooted and the anterior and posterior roots are joined by an isthmus. Despite these similarities, several differences are evident: the p3 crown and at least the apicalmost roots of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[163,308,811,832]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[163,181,811,832]" italics="true" pageId="19" pageNumber="1656">K</emphasis>
. 
<emphasis box="[200,308,811,832]" italics="true" pageId="19" pageNumber="1656">onamata</emphasis>
</taxonomicName>
are larger than in 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[563,721,811,832]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[563,579,811,832]" italics="true" pageId="19" pageNumber="1656">P</emphasis>
. 
<emphasis box="[598,721,811,832]" italics="true" pageId="19" pageNumber="1656">vasconum</emphasis>
</taxonomicName>
; the crown and accessory denticles of 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[576,730,842,863]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[576,592,842,863]" italics="true" pageId="19" pageNumber="1656">P</emphasis>
. 
<emphasis box="[610,730,842,863]" italics="true" pageId="19" pageNumber="1656">vasconum</emphasis>
</taxonomicName>
are more asymmetrical, with the anterior edge of the crown being more inclined relative to the anterior and posterior edges of the p3 of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[577,721,933,955]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[577,595,934,955]" italics="true" pageId="19" pageNumber="1656">K</emphasis>
. 
<emphasis box="[613,721,934,955]" italics="true" pageId="19" pageNumber="1656">onamata</emphasis>
</taxonomicName>
; the labial surface of the crown in 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[548,705,964,985]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[548,564,964,985]" italics="true" pageId="19" pageNumber="1656">P</emphasis>
. 
<emphasis box="[583,705,964,985]" italics="true" pageId="19" pageNumber="1656">vasconum</emphasis>
</taxonomicName>
lacks longitudinally elongate and ovoid abrasional occlusal wear facets; and the sulcus corresponding to the isthmus joining the anterior and posterior roots is more prominent in 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[407,550,1087,1108]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[407,425,1087,1108]" italics="true" pageId="19" pageNumber="1656">K</emphasis>
. 
<emphasis box="[443,550,1087,1108]" italics="true" pageId="19" pageNumber="1656">onamata</emphasis>
</taxonomicName>
and is difficult to discern in 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[281,424,1117,1139]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[281,297,1118,1139]" italics="true" pageId="19" pageNumber="1656">P</emphasis>
. 
<emphasis box="[310,424,1118,1139]" italics="true" pageId="19" pageNumber="1656">vasconum</emphasis>
</taxonomicName>
. Moreover, 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[554,697,1117,1139]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[554,570,1118,1139]" italics="true" pageId="19" pageNumber="1656">P</emphasis>
. 
<emphasis box="[583,697,1118,1139]" italics="true" pageId="19" pageNumber="1656">vasconum</emphasis>
</taxonomicName>
shares phenetic similarities with archaic toothed mysticetes from the Oligocene of South Carolina (
<bibRefCitation author="Geisler JH &amp; Boessenecker RW &amp; Brown M &amp; Beatty BL" pageId="19" pageNumber="1656" pagination="20361 - 2042" refId="ref24197" refString="Geisler JH, Boessenecker RW, Brown M, Beatty BL. 2017. The origin of filter feeding in whales. Current Biology 27: 20361 - 2042. e 2." type="journal article" year="2017">
Geisler 
<emphasis box="[714,772,1178,1200]" italics="true" pageId="19" pageNumber="1656">et al.</emphasis>
, 2017
</bibRefCitation>
) and even more so with 
<taxonomicName box="[536,731,1210,1231]" class="Mammalia" family="Inticetidae" genus="Inticetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vertizi">
<emphasis box="[536,731,1210,1231]" italics="true" pageId="19" pageNumber="1656">Inticetus vertizi</emphasis>
</taxonomicName>
, an enigmatic and contemporaneous large inticetid odontocete from the Burdigalian of 
<collectingCountry box="[600,656,1271,1292]" name="Peru" pageId="19" pageNumber="1656">Peru</collectingCountry>
(
<bibRefCitation author="Lambert O &amp; de Muizon C &amp; Malinverno E &amp; Di Celma C &amp; Urbina M &amp; Bianucci G" pageId="19" pageNumber="1656" pagination="981 - 1016" refId="ref25166" refString="Lambert O, de Muizon C, Malinverno E, Di Celma C, Urbina M, Bianucci G. 2018. A new odontocete (toothed cetacean) from the early Miocene of Peru expands the morphological disparity of extinct heterodont dolphins. Journal of Systematic Paleontology 16: 981 - 1016." type="journal article" year="2018">
Lambert 
<emphasis box="[163,220,1301,1323]" italics="true" pageId="19" pageNumber="1656">et al.</emphasis>
, 2018
</bibRefCitation>
). In agreement with 
<bibRefCitation author="Boessenecker RW" box="[536,773,1301,1323]" pageId="19" pageNumber="1656" pagination="93 - 103" refId="ref22330" refString="Boessenecker RW. 2019. Problematic archaic whale Phococetus (Cetacea: Odontoceti) from the Lee Creek Mine, North Carolina, USA, with comments on geochronology of the Pungo River Formation. PalZ 93: 93 - 103." type="journal article" year="2019">Boessenecker (2019)</bibRefCitation>
, several isolated teeth identified as cf. 
<taxonomicName box="[611,779,1332,1353]" class="Mammalia" genus="Phococetus" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="undetermined">
<emphasis box="[611,738,1332,1353]" italics="true" pageId="19" pageNumber="1656">Phococetus</emphasis>
sp.
</taxonomicName>
from the Pungo River Formation (Burdigalian) of Lee Creek Mine, North Carolina also resemble 
<taxonomicName box="[674,772,1393,1415]" class="Mammalia" family="Inticetidae" genus="Inticetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vertizi">
<emphasis box="[674,684,1394,1415]" italics="true" pageId="19" pageNumber="1656">I</emphasis>
. 
<emphasis box="[698,772,1394,1415]" italics="true" pageId="19" pageNumber="1656">vertizi</emphasis>
</taxonomicName>
, further suggesting that 
<taxonomicName authorityName="Gervais" authorityYear="1876" box="[468,602,1424,1445]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="genus">
<emphasis box="[468,602,1424,1445]" italics="true" pageId="19" pageNumber="1656">Phococetus</emphasis>
</taxonomicName>
has affinities within the Odontoceti. Thus, 
<taxonomicName baseAuthorityName="Delfortrie" baseAuthorityYear="1873" box="[520,779,1454,1476]" class="Mammalia" genus="Phococetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="vasconum">
<emphasis box="[520,779,1454,1476]" italics="true" pageId="19" pageNumber="1656">Phococetus vasconum</emphasis>
</taxonomicName>
is provisionally recognized as an 
<taxonomicName box="[590,698,1486,1507]" class="Mammalia" family="Inticetidae" genus="Inticetus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="genus">
<emphasis box="[590,698,1486,1507]" italics="true" pageId="19" pageNumber="1656">Inticetus</emphasis>
</taxonomicName>
-grade odontocete until taxonomic affinities can be confirmed by the discovery of more complete specimens.
</paragraph>
<paragraph blockId="19.[163,779,1609,1907]" lastBlockId="19.[827,1443,197,1691]" pageId="19" pageNumber="1656">
<emphasis box="[163,235,1609,1630]" italics="true" pageId="19" pageNumber="1656">Atlas:</emphasis>
The atlas represents the single preserved postcranial element in the 
<typeStatus box="[495,598,1640,1662]" pageId="19" pageNumber="1656">holotype</typeStatus>
of 
<taxonomicName authorityName=", Hector" authorityYear="1881" box="[639,778,1640,1661]" class="Mammalia" family="Basilosauridae" genus="Kekenodon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="19" pageNumber="1656" phylum="Chordata" rank="species" species="onamata">
<emphasis box="[639,657,1640,1661]" italics="true" pageId="19" pageNumber="1656">K</emphasis>
. 
<emphasis box="[673,778,1640,1661]" italics="true" pageId="19" pageNumber="1656">onamata</emphasis>
</taxonomicName>
and is not fused to the axis (
<figureCitation box="[528,599,1670,1692]" captionStart="Figure 9" captionStartId="20.[145,226,1503,1525]" captionTargetBox="[147,1419,198,1461]" captionTargetId="figure-173@20.[145,1425,195,1463]" captionTargetPageId="20" captionText="Figure 9. Atlas of Kekenodon onamata (NMNZ Ma 306). A, anterior view. B, posterior view. Specimen whitened with ammonium chloride." figureDoi="http://doi.org/10.5281/zenodo.7381132" httpUri="https://zenodo.org/record/7381132/files/figure.png" pageId="19" pageNumber="1656">Fig. 9</figureCitation>
; 
<tableCitation box="[615,707,1670,1692]" captionStart="Table 5" captionStartId="21.[161,225,866,887]" captionTargetBox="[161,776,1041,1420]" captionTargetPageId="21" captionText="Table 5. Measurements (in mm) of the holotype atlas" pageId="19" pageNumber="1656">Table 5</tableCitation>
). The atlas is ovoid in anterior view, anteroposteriorly thick and transversely broad. In lateral view, the anteroposterior length of the atlas increases dorsally and narrows ventrally. A break along the ventral arch bisects the atlas into subequal left and right parts, which have been rejoined by an adhesive. The eroded reniform anterior articular surfaces, or condyloid fossae, for the occipital condyles are dorsoventrally tall, shallowly concave and oriented dorsolaterally. The condyloid fossae are mediolaterally broadest at a level just ventral to the base of the transverse processes. In life, the margins of the condyloid fossae were probably marked by crests, now eroded. The neural canal is proportionally large and pyriform, with a transverse diameter that ventrally tapers and dorsally broadens; weathering may have altered the dimensions of the neural canal. The condyloid fossae are too damaged to judge whether they were angled or parallel to the posterior articular surfaces in order to interpret head orientation relative to the body axis. The preserved bases of the left and right neural pedicles project dorsomedially and anteriorly from the dorsal surface of the vertebral body. Additionally, the bases of the left and right transverse processes are preserved, and project dorsolaterally and posteriorly from the dorsolateral surface of the vertebral body; the transverse processes are located ventral and slightly posterior to the neural arch. The medialmost section of the transverse processes has a dorsoventrally oriented ovoid cross-section in lateral view. There is no indication of a vertebrarterial canal. In left-lateral view, a U-shaped depression on the anterodorsal surface of the vertebral body denotes the position of the transversely oriented left transverse foramen (for the first spinal nerve); the right foramen is not preserved. The ventral margin of the transverse foramen is level with the preserved dorsal margin of the base of the left transverse process, with the foramen opening mediolaterally.
</paragraph>
<paragraph blockId="19.[827,1443,197,1691]" pageId="19" pageNumber="1656">
The posterior articulating surfaces for the axis are reniform with a dorsoventral long axis and are planar to slightly convex. The mediolateral broadest point of the posterior articulating surfaces (
<quantity box="[1297,1405,1270,1292]" metricMagnitude="-2" metricUnit="m" metricValue="4.56" pageId="19" pageNumber="1656" unit="mm" value="45.6">45.6 mm</quantity>
) is located just ventral to the ventral margin of the base of the transverse processes (measurement taken from the left posterior articulating facet). The odontoid fossa is located medial to the posterior articular surfaces and forms the posteroventral margin of the neural canal. The odontoid fossa is concave and rises dorsolaterally toward the posterolateral margins of the neural canal. There is no indication of developed tubercles for the transverse ligament, which would separate the odontoid region (ventrally) from the neural canal (dorsally). The preserved hypapophysis is relatively indistinct and projects posteroventrally from the posteroventral margin of the ventral arch.
</paragraph>
</subSubSection>
</treatment>
</document>