293 lines
58 KiB
XML
293 lines
58 KiB
XML
<document ID-DOI="10.7717/peerj.2321" ID-GBIF-Dataset="bfee38ac-d1ef-47d5-b4a3-ffa07cc53f18" ID-PMC="PMC4991871" ID-PubMed="27602287" ID-Zenodo-Dep="270212" checkinTime="1472036144924" checkinUser="plazi" docAuthor="Alexandra T. Boersma & Nicholas D. Pyenson" docDate="2016" docId="E03BF937AF24FFF10484FBECFA6FDB34" docLanguage="en" docName="peerj-2321.pdf" docOrigin="Peerj 2321" docStyle="DocumentStyle{}" docTitle="Allodelphinidae" docType="treatment" docVersion="17" lastPageNumber="33" masterDocId="1C02814FAF3FFFD1056FFFD3FF93DC0D" masterDocTitle="Arktocara yakataga, a new fossil odontocete (Mammalia, Cetacea) from the Oligocene of Alaska and the antiquity of Platanistoidea" masterLastPageNumber="41" masterPageNumber="1" pageNumber="28" updateTime="1668138771274" updateUser="ExternalLinkService">
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<mods:titleInfo>
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<mods:title>Arktocara yakataga, a new fossil odontocete (Mammalia, Cetacea) from the Oligocene of Alaska and the antiquity of Platanistoidea</mods:title>
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</mods:titleInfo>
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<mods:name type="personal">
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<mods:role>
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<mods:roleTerm>Author</mods:roleTerm>
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<mods:namePart>Alexandra T. Boersma</mods:namePart>
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</mods:name>
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<mods:name type="personal">
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<mods:role>
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<mods:roleTerm>Author</mods:roleTerm>
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</mods:role>
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<mods:namePart>Nicholas D. Pyenson</mods:namePart>
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</mods:name>
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<mods:typeOfResource>text</mods:typeOfResource>
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<mods:title>Peerj</mods:title>
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<mods:part>
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<mods:date>2016</mods:date>
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<mods:detail type="volume">
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<mods:number>2321</mods:number>
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<mods:start>1</mods:start>
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<mods:end>41</mods:end>
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<mods:classification>journal article</mods:classification>
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<mods:identifier type="DOI">10.7717/peerj.2321</mods:identifier>
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<mods:identifier type="GBIF-Dataset">bfee38ac-d1ef-47d5-b4a3-ffa07cc53f18</mods:identifier>
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<mods:identifier type="PMC">PMC4991871</mods:identifier>
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<mods:identifier type="PubMed">27602287</mods:identifier>
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<mods:identifier type="Zenodo-Dep">270212</mods:identifier>
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<treatment ID-DOI="http://doi.org/10.5281/zenodo.5658612" ID-GBIF-Taxon="124407768" ID-Zenodo-Dep="5658612" LSID="urn:lsid:plazi:treatment:E03BF937AF24FFF10484FBECFA6FDB34" httpUri="http://treatment.plazi.org/id/E03BF937AF24FFF10484FBECFA6FDB34" lastPageId="32" lastPageNumber="33" pageId="27" pageNumber="28">
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<subSubSection box="[491,962,1087,1116]" pageId="27" pageNumber="28" type="nomenclature">
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<paragraph blockId="27.[491,1542,1087,1913]" box="[491,962,1087,1116]" pageId="27" pageNumber="28">
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<heading bold="true" box="[491,962,1087,1116]" fontSize="12" level="2" pageId="27" pageNumber="28" reason="0">
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<emphasis bold="true" box="[491,962,1087,1116]" pageId="27" pageNumber="28">
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Systematics of
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<taxonomicName box="[725,962,1087,1116]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="27" pageNumber="28" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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</emphasis>
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</heading>
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</paragraph>
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</subSubSection>
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<subSubSection lastPageId="29" lastPageNumber="30" pageId="27" pageNumber="28" type="discussion">
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<paragraph blockId="27.[491,1542,1087,1913]" lastBlockId="28.[491,1542,228,1913]" lastPageId="28" lastPageNumber="29" pageId="27" pageNumber="28">
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Our analysis recovered
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<taxonomicName box="[771,957,1129,1155]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="27" pageNumber="28" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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as a wellsupported subclade within a nodebased Platanistoidea, rooted in a polytomy with Squalodelphis fabianii and an unnamed subclade that includes Notocetus vanbenedeni C Phocageneus venustus C
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<taxonomicName box="[1358,1510,1209,1235]" class="Mammalia" family="Platanistidae" kingdom="Animalia" order="Cetacea" pageId="27" pageNumber="28" phylum="Chordata" rank="family">Platanistidae</taxonomicName>
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.
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<taxonomicName box="[491,677,1249,1275]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="27" pageNumber="28" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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in our study is supported by the following synapomorphies: rostral constriction anterior to the antorbital notch (character 9[1]); premaxillae in dorsal view contacting along midline for approximately half of the entire length of the rostrum and partially fused (character 14[3]); buccal teeth entocingulum absent (character 24[1]); greatest diameter of largest functional tooth <3% of greatest width of maxillae at postorbital processes (character 25[2]); angle of anterior edge of supraorbital process and the median line oriented anteromedially (character 35[1]); dorsolateral edge of internal opening of infraorbital foramen formed by maxilla (character 43[0]); posterolateral sulcus shallow or absent (character 57[1]); lack of premaxillary crest or posterior maxillary crest adjacent to nasals (character 72[0]); temporal fossa roofed over by lateral expansion of the maxillae (character 101[1]); palatines partially covered by pterygoid dividing it into medial and lateral exposures (character 121[1]); lateral lamina of palatine (character 122[1]); lateral end of groove for mandibular branch of trigeminal nerve wrapping laterally around posterior end of pterygoid sinus fossa and opening anteriorly (character 148[0]); lack of anterior bullar facet (character 172[1]); elevated caudal tympanic process of periotic with ventral and posterior edges forming a right angle in medial view (character 178[1]); tubular fundus of internal acoustic meatus (character 182[1]) angle between posterior process of periotic and long axis of pars cochlearis 135 from dorsal or ventral view (character 189[1]); and ventral surface of posterior process of periotic convex along a straight path perpendicular to its long axis (character 191[2]). Based on the published descriptions and illustrations provided by
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<bibRefCitation author="Kimura T & Barnes LG." box="[527,810,347,373]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="28" pageNumber="29" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes (2016)</bibRefCitation>
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, the three allodelphinid taxa not included in our phylogenetic analysis (Allodelphis woodburnei, Ninjadelphis ujiharai, and Zarhinocetus donnamatsonae) each possess all of the allodelphinid synapomorphies presented by our analysis.
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</paragraph>
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<paragraph blockId="28.[491,1542,228,1913]" pageId="28" pageNumber="29">
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In their review of
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<taxonomicName authority="Kimura & Barnes (2016)" authorityName="Kimura & Barnes" authorityYear="2016" box="[739,1224,465,492]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">
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Allodelphinidae,
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<bibRefCitation author="Kimura T & Barnes LG." box="[941,1224,466,492]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="28" pageNumber="29" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes (2016)</bibRefCitation>
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</taxonomicName>
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based their diagnosis of this group on comparative characters rather than phylogenetic synapomorphies. Many of these comparative characters can be readily observed in all platanistoids, such as the posteriorly extended lateral lamina of the pterygoid and palatine (except in species of Waipatia and Otekaikea where the palatine is poorly preserved or missing), and a tympanic bulla with elongated and pointed anterior process, among others. Nevertheless, our
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</paragraph>
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<paragraph blockId="28.[491,1542,228,1913]" pageId="28" pageNumber="29">
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diagnosis is consistent with
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<bibRefCitation author="Kimura T & Barnes LG." box="[823,1106,703,729]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="28" pageNumber="29" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes (2016)</bibRefCitation>
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’s concept of
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<taxonomicName box="[1266,1452,702,728]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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with only two exceptions. First,
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<bibRefCitation author="Kimura T & Barnes LG." box="[814,1098,742,768]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="28" pageNumber="29" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes (2016)</bibRefCitation>
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report that, in allodelphinids, the posterior ends of the premaxillae are separated from the lateral sides of the corresponding nasal bones, beginning with a more ‘‘primitive’’ state in Allodelphis pratti where only one premaxilla is separated from the corresponding nasal by a tiny exposure of maxilla, to further ‘‘derived’’ states in Ninjadelphis and Zarhinocetus where the premaxillae are further retracted anteriorly onto the facial region and away from the nasals. However, it is unclear in the more ‘‘primitive’’ state of Allodelphis whether the lack of contact between the premaxilla and nasal could be a result of diagenetic breakage, or individual variation. Furthermore, speculations on the more ‘‘derived states’’ in taxa such as Ninjadelphis, are based on specimens with incomplete premaxillae. In Goedertius oregonensis, the premaxillae are not separated from the nasals. This condition is likely also true for Arktocara yakataga: although the nasals are missing, the premaxillae directly abut the nasal fossa of the frontal, and therefore would most likely have been in direct contact with the nasals. Further extensive comparative work on allodelphinid taxa (including the multiple specimens housed at
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<collectionCode box="[611,694,1295,1321]" country="USA" httpUri="http://biocol.org/urn:lsid:biocol.org:col:34871" name="Smithsonian Institution, National Museum of Natural History" pageId="28" pageNumber="29">USNM</collectionCode>
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that can readily be referred to Goedertius sp. (Fig. S2)) will help to clarify the distribution and diagnostic utility of these traits.
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</paragraph>
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<paragraph blockId="28.[491,1542,228,1913]" pageId="28" pageNumber="29">
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Second,
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<bibRefCitation author="Kimura T & Barnes LG." box="[624,908,1374,1400]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="28" pageNumber="29" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes (2016)</bibRefCitation>
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diagnosed
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<taxonomicName box="[1044,1230,1374,1400]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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by an absence of both the preorbital and postorbital lobe of the pterygoid sinus. Both fossae for the pre and postorbital lobe of the pterygoid sinus are unclear in the
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<typeStatus box="[1140,1190,1453,1479]" pageId="28" pageNumber="29">type</typeStatus>
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specimen of Allodelphis pratti, in part due to obstruction by unprepared matrix. However, in Arktocara yakataga, though there is no obvious indication of a postorbital lobe of the pterygoid sinus, the deep and broad fossa surrounding the ventral infraorbital foramen and the sphenopalatine foramen anteromedial of the orbit suggests the presence of a preorbital lobe.
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</paragraph>
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<paragraph blockId="28.[491,1542,228,1913]" lastBlockId="29.[491,1542,228,733]" lastPageId="29" lastPageNumber="30" pageId="28" pageNumber="29">
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Originally assigned to
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<taxonomicName box="[789,938,1650,1676]" class="Mammalia" family="Platanistidae" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">Platanistidae</taxonomicName>
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by
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<bibRefCitation author="Wilson LE." box="[984,1146,1651,1677]" journalOrPublisher="California. Peabody Museum of Natural History Bulletin" pageId="28" pageNumber="29" pagination="13" part="4" refString="Wilson LE. 1935. Miocene marine mammals from the Bakersfield region, California. Peabody Museum of Natural History Bulletin 4: 13 26." title="Miocene marine mammals from the Bakersfield region" type="journal article" year="1935">Wilson (1935)</bibRefCitation>
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, Allodelphis pratti was referred to the
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<taxonomicName box="[573,722,1690,1716]" class="Mammalia" family="Platanistidae" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">Platanistidae</taxonomicName>
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by
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<bibRefCitation author="Barnes LG." box="[770,930,1690,1716]" journalOrPublisher="Systematic Zoology" pageId="28" pageNumber="29" pagination="321" part="25" refString="Barnes LG. 1977. Outline of eastern North Pacific fossil cetacean assemblages. Systematic Zoology 25: 321 343." title="Outline of eastern North Pacific fossil cetacean assemblages" type="journal article" year="1977">Barnes (1977)</bibRefCitation>
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, and later
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<bibRefCitation author="Barnes LG." box="[1064,1223,1690,1716]" journalOrPublisher="Beitrage zur Palaontologie" pageId="28" pageNumber="29" pagination="25" part="30" refString="Barnes LG. 2006. A phylogenetic analysis of the superfamily Platanistoidea (Mammalia, Cetacea, Odontoceti). Beitrage zur Palaontologie 30: 25 42." title="A phylogenetic analysis of the superfamily Platanistoidea (Mammalia, Cetacea, Odontoceti)" type="journal article" year="2006">Barnes (2006)</bibRefCitation>
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erected a new group,
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<taxonomicName box="[491,680,1729,1755]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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, for it. However, in both instances,
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<bibRefCitation author="Barnes LG." box="[1114,1273,1730,1756]" journalOrPublisher="Systematic Zoology" pageId="28" pageNumber="29" pagination="321" part="25" refString="Barnes LG. 1977. Outline of eastern North Pacific fossil cetacean assemblages. Systematic Zoology 25: 321 343." title="Outline of eastern North Pacific fossil cetacean assemblages" type="journal article" year="1977">Barnes (1977)</bibRefCitation>
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and
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<bibRefCitation author="Barnes LG." box="[1337,1497,1730,1756]" journalOrPublisher="Beitrage zur Palaontologie" pageId="28" pageNumber="29" pagination="25" part="30" refString="Barnes LG. 2006. A phylogenetic analysis of the superfamily Platanistoidea (Mammalia, Cetacea, Odontoceti). Beitrage zur Palaontologie 30: 25 42." title="A phylogenetic analysis of the superfamily Platanistoidea (Mammalia, Cetacea, Odontoceti)" type="journal article" year="2006">Barnes (2006)</bibRefCitation>
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did not provide an explanation for why the
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<taxonomicName box="[1006,1192,1769,1795]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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belong to the Platanistoidea. Of the 7 synapomorphies for Platanistoidea identified by our phylogenetic analysis, the
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<taxonomicName box="[491,677,1848,1874]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="28" pageNumber="29" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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possessed 4 of the 5 unequivocal characters: lateral groove or depression with profile of periotic becoming slightly to markedly sigmoidal in dorsal view (character 166[1]); anteroposterior ridge on dorsal side anterior process and body of periotic (character 167[1]); parabullary sulcus on the periotic weakly to strongly curved and cshaped (character 169[1,2]); and ventral surface of the posterior process of the periotic not flat along a straight path perpendicular to its long axis (character 191[1,2]). The fifth unequivocal character (147), could not be observed in any of the
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<taxonomicName box="[1224,1410,388,414]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="29" pageNumber="30" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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specimens. In addition, the
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<typeStatus box="[682,732,428,454]" pageId="29" pageNumber="30">type</typeStatus>
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specimen of Ninjadelphis is the only allodelphinid specimen with an associated scapula, and it is missing the coracoid process. This agreement with Muizon’ s (1987) platanistoid synapomorphy the loss or reduction of the coracoid process of the scapula suggests that, though the process is still present in some putative platanistoids (i.e., Otekaikea huata), the character may still be relevant for diagnosing Platanistoidea (
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<bibRefCitation author="Kimura T & Barnes LG." box="[502,771,627,653]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="29" pageNumber="30" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes, 2016</bibRefCitation>
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). We urge future studies on
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<taxonomicName box="[1098,1284,627,653]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="29" pageNumber="30" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
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to not only include all available genera (if not putative species), but also to explicitly test phylogenetic hypotheses in a repeatable analytical framework.
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</paragraph>
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</subSubSection>
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<subSubSection lastPageId="31" lastPageNumber="32" pageId="29" pageNumber="30" type="diagnosis">
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<paragraph blockId="29.[491,1542,768,1913]" box="[491,917,768,797]" pageId="29" pageNumber="30">
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<heading bold="true" box="[491,917,768,797]" fontSize="12" level="2" pageId="29" pageNumber="30" reason="0">
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<emphasis bold="true" box="[491,917,768,797]" pageId="29" pageNumber="30">Morphological comparisons</emphasis>
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</heading>
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</paragraph>
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<paragraph blockId="29.[491,1542,768,1913]" pageId="29" pageNumber="30">
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Of the 7 supporting synapomorphies for Platanistoidea in our study, none of the unequivocal synapomorphies are preserved and demonstrated on the skull of Arktocara. However, one equivocal synapomorphy is preserved in Arktocara: width of the premaxillae>50% of the width of the rostrum at the antorbital notch (character 51[1]). Though the
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<typeStatus box="[491,541,970,996]" pageId="29" pageNumber="30">type</typeStatus>
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specimen of Arktocara lacks tympanoperiotics, it is closely allied with Allodelphis pratti, whose periotic shares three more of the platanistoid synapomorphies: presence of lateral groove or depression with the profile of the periotic becoming slightly to markedly sigmoidal in in dorsal view (character 166[1]); anteroposterior ridge developed on anterior process and body of periotic in dorsal view (character 167[1]); and a curved Cshaped parabullary sulcus (character 169[2]; see
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<figureCitation box="[838,904,1169,1195]" captionStart="Figure 9" captionStartId="10.[507,571,1570,1592]" captionTargetBox="[491,1541,229,1525]" captionTargetId="figure@10.[491,1541,229,1525]" captionTargetPageId="10" captionText="Figure 9 Right periotic of the holotype of Allodelphis pratti (YPM 13408). Right periotic of Allodelphis pratti in dorsal (A, B), and lateral (C, D) views. (A, C), Illustrated periotic with low opacity mask and interpretive line art. The two periotic synapomorphies for the Platanistoidea are labelled: the parabullary sulcus, and the dorsal crest. (B, D), photography by James Di Loreto, Smithsonian Institution. Courtesy of the Division of Vertebrate Paleontology; YPM 13408, Peabody Museum of Natural History, Yale University, New Haven, Connecticut, USA; peabody. yale. edu." httpUri="https://zenodo.org/record/270221/files/figure.png" pageId="29" pageNumber="30">Fig. 9</figureCitation>
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for illustration of the periotic synapomorphies on the
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<typeStatus box="[537,587,1209,1235]" pageId="29" pageNumber="30">type</typeStatus>
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specimen of Allodelphis pratti). Therefore, in the absence of tympanoperiotics associated with new cranial material of Arktocara, we are confident that these elements would share many features with Allodelphis pratti, the sister taxon of Arktocara.
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</paragraph>
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<paragraph blockId="29.[491,1542,768,1913]" lastBlockId="30.[491,1542,228,1913]" lastPageId="30" lastPageNumber="31" pageId="29" pageNumber="30">
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Overall, the allodelphinid that most resembles Arktocara in morphology is Allodelphis pratti (
|
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<figureCitation box="[575,680,1368,1394]" captionStart-0="Figure 7" captionStart-1="Figure 8" captionStart-2="Figure 9" captionStartId-0="8.[507,571,903,925]" captionStartId-1="9.[507,571,895,917]" captionStartId-2="10.[507,571,1570,1592]" captionTargetBox-0="[491,1515,229,858]" captionTargetBox-1="[491,1541,229,850]" captionTargetBox-2="[491,1541,229,1525]" captionTargetId-0="figure@8.[491,1515,229,858]" captionTargetId-1="figure@9.[491,1541,229,850]" captionTargetId-2="figure@10.[491,1541,229,1525]" captionTargetPageId-0="8" captionTargetPageId-1="9" captionTargetPageId-2="10" captionText-0="Figure 7 Skull of the holotype of Allodelphis pratti (YPM 13408) in dorsal view. (A) Illustrated skull with low opacity mask, interpretive line art, and labels for skull elements. Dotted lines indicate uncer tainty of sutures and hatched lines indicate sediment obscuring the fossil. The symbol ‘‘? ’’ denotes a displaced skull fragment of unknown origin. (B) photograph of skull in dorsal view, photography by James Di Loreto, Smithsonian Institution. Courtesy of the Division of Vertebrate Paleontology; YPM 13408, Peabody Museum of Natural History, Yale University, New Haven, Connecticut, USA; peabody. yale. edu." captionText-1="Figure 8 Skull of the holotype of Allodelphis pratti (YPM 13408) in ventral view. (A) Illustrated skull with low opacity mask, interpretive line art, and labels for skull elements. Dotted lines indicate uncer tainty of sutures and hatched lines indicate sediment obscuring the fossil. The symbol ‘‘? ’’ denotes a displaced skull fragment of unknown origin. (B) photograph of skull in ventral view, photography by James Di Loreto, Smithsonian Institution. Courtesy of the Division of Vertebrate Paleontology; YPM 13408, Peabody Museum of Natural History, Yale University, New Haven, Connecticut, USA; peabody. yale. edu." captionText-2="Figure 9 Right periotic of the holotype of Allodelphis pratti (YPM 13408). Right periotic of Allodelphis pratti in dorsal (A, B), and lateral (C, D) views. (A, C), Illustrated periotic with low opacity mask and interpretive line art. The two periotic synapomorphies for the Platanistoidea are labelled: the parabullary sulcus, and the dorsal crest. (B, D), photography by James Di Loreto, Smithsonian Institution. Courtesy of the Division of Vertebrate Paleontology; YPM 13408, Peabody Museum of Natural History, Yale University, New Haven, Connecticut, USA; peabody. yale. edu." httpUri-0="https://zenodo.org/record/270219/files/figure.png" httpUri-1="https://zenodo.org/record/270220/files/figure.png" httpUri-2="https://zenodo.org/record/270221/files/figure.png" pageId="29" pageNumber="30">Figs. 7 9</figureCitation>
|
||
), originally described by
|
||
<bibRefCitation author="Wilson LE." box="[984,1145,1369,1395]" journalOrPublisher="California. Peabody Museum of Natural History Bulletin" pageId="29" pageNumber="30" pagination="13" part="4" refString="Wilson LE. 1935. Miocene marine mammals from the Bakersfield region, California. Peabody Museum of Natural History Bulletin 4: 13 26." title="Miocene marine mammals from the Bakersfield region" type="journal article" year="1935">Wilson (1935)</bibRefCitation>
|
||
from the Jewett Sand in Kern County,
|
||
<collectingRegion box="[596,716,1408,1434]" country="United States of America" name="California" pageId="29" pageNumber="30">California</collectingRegion>
|
||
,
|
||
<collectingCountry box="[730,788,1408,1434]" name="United States of America" pageId="29" pageNumber="30">USA</collectingCountry>
|
||
. Having examined the
|
||
<typeStatus box="[1066,1168,1408,1434]" pageId="29" pageNumber="30">holotype</typeStatus>
|
||
consisting of a skull with associated rostrum and jaw fragments, other skull fragments, and a right periotic we note that the material included in the
|
||
<typeStatus box="[881,983,1488,1514]" pageId="29" pageNumber="30">holotype</typeStatus>
|
||
actually belongs to more than one individual. For example, the
|
||
<typeStatus box="[697,799,1528,1554]" pageId="29" pageNumber="30">holotype</typeStatus>
|
||
includes an isolated left postglenoid process, even though the
|
||
<typeStatus box="[491,593,1568,1594]" pageId="29" pageNumber="30">holotype</typeStatus>
|
||
skull still has this feature intact. However, having examined the right periotic in relation to the periotic fossa, we are confident in the association of this element to the
|
||
<typeStatus box="[491,593,1647,1673]" pageId="29" pageNumber="30">holotype</typeStatus>
|
||
skull. Any further study including the
|
||
<typeStatus box="[1056,1158,1647,1673]" pageId="29" pageNumber="30">holotype</typeStatus>
|
||
of Allodelphis should take this caveat into consideration. Allodelphis is similar in size and shape to the
|
||
<typeStatus box="[1329,1379,1687,1713]" pageId="29" pageNumber="30">type</typeStatus>
|
||
of Arktocara, with wide, hexagonally shaped craniums and postorbital widths within
|
||
<quantity box="[1348,1407,1727,1753]" metricMagnitude="-2" metricUnit="m" metricValue="2.0" pageId="29" pageNumber="30" unit="cm" value="2.0">2 cm</quantity>
|
||
of one another. In dorsal view, the two genera are alike in having their premaxillae rise above the maxillae for the entire length of the cranium from the level of the antorbital notch to the cranial vertex, forming an anteroposteriorly elongated and dorsally elevated plateau in relation to the broad, flat maxilla across the facial region. In both genera, this premaxillary plateau continues posteriorly to a tabular vertex, posterior to the external bony nares. The exposures of the frontals and nasals are symmetrical on the vertex, and there is no evident leftward skew or other facial asymmetry. The nasals are also transversely widened anteriorly, setting these two genera apart from all other allodelphinids.
|
||
<bibRefCitation author="Kimura T & Barnes LG." journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="30" pageNumber="31" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes (2016)</bibRefCitation>
|
||
showed photos of the
|
||
<typeStatus box="[843,945,386,412]" pageId="30" pageNumber="31">holotype</typeStatus>
|
||
of Allodelphis pratti with a feature on the skull labeled ‘‘posterior dorsal infraorbital foramen.’’ However, having examined the
|
||
<typeStatus box="[1427,1532,426,452]" pageId="30" pageNumber="31">holotype</typeStatus>
|
||
, we do not see any evidence of a posterior infraorbital foramina the featured labelled in the photo is a small break in the maxilla overlying the frontal. While it is possible that a posterior dorsal infraorbital foramen is hidden under the jaw fragment that is adhered to the right maxilla, we refrain from definitively stating any foramen exists. Both Arktocara yakataga and Allodelphis pratti have a nuchal crest weakly convex anteriorly, a widely open mesorostral canal anterior to the bony nares, the maxilla covering almost all of the frontal along the supraorbital process, and the posterior end of the basioccipital crest separated from the rest of the crest by a narrow crease.
|
||
</paragraph>
|
||
<paragraph blockId="30.[491,1542,228,1913]" pageId="30" pageNumber="31">The coded character state differences between Arktocara yakataga and Allodelphis pratti are listed in the Diagnosis section, above, although we provide more descriptive differences between these two taxa, as follows. First, Arktocara differs from Allodelphis in dorsal view by having: a deeper mesorostral canal anterior to the external nares; straight lateral margins of the premaxillae lateral and posterior of the external nares; no exposure of the maxillae on the vertex; a greater transverse constriction of the lateral margins of the maxilla/frontal anterior to the nuchal crest; a less extreme flaring of the posterior temporal crest along the occipital border; and more prominent dorsal infraorbital foramina, with posteriorly directed sulci. In lateral view, Arktocara shows a markedly reduced postglenoid process and zygomatic process of the squamosal, and a more posterolaterally directed postorbital process as opposed to a ventrally oriented process in Allodelphis. In ventral view, Arktocara has a more elevated vomerine keel. We argue that these differences, along with those coded in the phylogenetic analysis, provide the basis for Arktocara yakataga’ s status as a new genus of allodelphinid.</paragraph>
|
||
<paragraph blockId="30.[491,1542,228,1913]" pageId="30" pageNumber="31">
|
||
Arktocara also differs in clear ways from three allodelphinids (sensu
|
||
<bibRefCitation author="Kimura T & Barnes LG." journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="30" pageNumber="31" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes, 2016</bibRefCitation>
|
||
) that were not included in the phylogenetic analysis: Ninjadelphis ujiharai, Allodelphis woodburnei, and Zarhinocetus donnamatsonae. Arktocara differs from both Ninjadelphis ujiharai and Zarhinocetus donnamatsonae in having: a wider opening of the mesorostral canal, anterior to the external nares in dorsal view; anteroposteriorly straight lateral margins of the premaxillae both lateral and posterior of the external bony nares, in dorsal view; the posterior ends of the premaxillae extending posterior of the nasals; nasals expanding in width anteriorly rather than narrowing anteriorly; a reduced postglenoid process; and a broader extent of the maxilla above the supraorbital process of the frontal. Arktocara further differs from both Ninjadelphis ujiharai and Zarhinocetus donnamatsonae in lacking a dorsal depression on the base of the rostrum formed by ventromedially sloping of the premaxillae and maxillae, and lacking an asymmetrical skew to the vertex or nuchal crest.
|
||
</paragraph>
|
||
<paragraph blockId="30.[491,1542,228,1913]" lastBlockId="31.[491,1541,228,653]" lastPageId="31" lastPageNumber="32" pageId="30" pageNumber="31">Arktocara further differs from Ninjadelphis ujiharai in: lacking exposures of the maxillae on the vertex; lacking a glenoid fossa facing anteriorly as opposed to anteromedially; lacking widely diverging basioccipital crests; and lacking a depressed pit of the posterior end of the maxilla with an overhanging lip of the nuchal crest. Arktocara also differs from Zarhinocetus donnamatsonae in having: a more prominent and flaring temporal crest; a zygomatic process more tapered anteriorly in lateral view; the absence of a maxillary tuberosity on the lateral edge of the maxillary flange immediately anterior to the antorbital notch; no reduction of the maxilla on the supraorbital process to expose a thick band of frontal; and lacking a maxillary crest on the supraorbital process in dorsal view. Arktocara differs from Allodelphis woodburnei in having: a smaller and more anteriorly tapered zygomatic process; a reduced postglenoid process; the absence of a prominent fossa on each side of the sagittal crest on the supraoccipital; the premaxillae sloping medially towards the mesorostral canal on the posterior rostrum; and a glenoid fossa directed anteriorly rather than anteroventrally.</paragraph>
|
||
</subSubSection>
|
||
<subSubSection lastPageId="32" lastPageNumber="33" pageId="31" pageNumber="32" type="distribution">
|
||
<paragraph blockId="31.[491,1542,688,1913]" box="[491,1060,688,717]" pageId="31" pageNumber="32">
|
||
<heading bold="true" box="[491,1060,688,717]" fontSize="12" level="2" pageId="31" pageNumber="32" reason="0">
|
||
<emphasis bold="true" box="[491,1060,688,717]" pageId="31" pageNumber="32">Geological & geographic significance</emphasis>
|
||
</heading>
|
||
</paragraph>
|
||
<paragraph blockId="31.[491,1542,688,1913]" pageId="31" pageNumber="32">
|
||
Today,
|
||
<taxonomicName box="[582,696,731,757]" class="Mammalia" family="Platanistidae" genus="Platanista" kingdom="Animalia" order="Cetacea" pageId="31" pageNumber="32" phylum="Chordata" rank="genus">Platanista</taxonomicName>
|
||
gangetica is distributed in two subspecies across the Indus, Ganges BrahmaputraMegna and KarnaphuliSangu river systems of Southeast Asia, and remains highly threatened by human activities, including bycatch, fishing, and habitat modification (e.g.,
|
||
<bibRefCitation author="Braulik GT & Arshad M & Noureen U & Northridge SP." box="[556,784,851,877]" journalOrPublisher="PLoS ONE" pageId="31" pageNumber="32" pagination="7" part="9" publicationUrl="10.1371/journal.pone.0101657." refString="Braulik GT, Arshad M, Noureen U, Northridge SP. 2014 a. Habitat fragmentation and species extirpation in freshwater ecosystems; causes of range decline of the Indus River Dolphin (Platanista gangetica minor). PLoS ONE 9 (7): e 101657 DOI 10.1371 / journal. pone. 0101657." title="Habitat fragmentation and species extirpation in freshwater ecosystems; causes of range decline of the Indus River Dolphin (Platanista gangetica minor)" type="journal article" year="2014" yearSuffix="a">Braulik et al., 2014a</bibRefCitation>
|
||
). The fossil record of all other Platanistoidea demonstrates that the immediate relatives of
|
||
<taxonomicName box="[803,917,890,916]" class="Mammalia" family="Platanistidae" genus="Platanista" kingdom="Animalia" order="Cetacea" pageId="31" pageNumber="32" phylum="Chordata" rank="genus">Platanista</taxonomicName>
|
||
gangetica comprise a morphologically diverse group of small to medium sized odontocetes that are distributed globally in marine sediments of Oligocene and Miocene age (see
|
||
<bibRefCitation author="Bianucci G & Lambert L & Salas-Gismondi R & Tejada J & Pujos F & Urbina M & Antoine P-O." box="[860,1102,970,996]" journalOrPublisher="Journal of Vertebrate Paleontology" pageId="31" pageNumber="32" pagination="741" part="33" publicationUrl="10.1080/02724634.2013.734888." refString="Bianucci G, Lambert L, Salas-Gismondi R, Tejada J, Pujos F, Urbina M, Antoine P-O. 2013. A Miocene relative of the Ganges River dolphin (Odontoceti, Platanistidae) from the Amazonian Basin. Journal of Vertebrate Paleontology 33 (3): 741 745 DOI 10.1080 / 02724634.2013.734888." title="A Miocene relative of the Ganges River dolphin (Odontoceti, Platanistidae) from the Amazonian Basin" type="journal article" year="2013">Bianucci et al. (2013)</bibRefCitation>
|
||
and
|
||
<bibRefCitation author="Hulbert RC & Whitmore Jr FC." box="[1155,1503,970,996]" journalOrPublisher="Alabama. Bulletin of the Florida Museum of Natural History" pageId="31" pageNumber="32" pagination="1" part="46" refString="Hulbert RC, Whitmore Jr FC. 2006. Late Miocene mammals from the Mauvilla Local Fauna, Alabama. Bulletin of the Florida Museum of Natural History 46 (1): 1 28." title="Late Miocene mammals from the Mauvilla Local Fauna" type="journal article" year="2006">Hulbert & Whitmore Jr (2006)</bibRefCitation>
|
||
for two exceptional occurrences of platanistid specimens in freshwater sediments of
|
||
<collectingCountry box="[1434,1489,1010,1036]" name="Peru" pageId="31" pageNumber="32">Peru</collectingCountry>
|
||
and
|
||
<collectingRegion box="[491,597,1050,1076]" country="United States of America" name="Alabama" pageId="31" pageNumber="32">Alabama</collectingRegion>
|
||
, respectively). There is no fossil record for the genus
|
||
<taxonomicName box="[1221,1335,1050,1076]" class="Mammalia" family="Platanistidae" genus="Platanista" kingdom="Animalia" order="Cetacea" pageId="31" pageNumber="32" phylum="Chordata" rank="genus">Platanista</taxonomicName>
|
||
, but recent work on mitochondrial
|
||
<collectionCode box="[708,770,1089,1115]" country="Australia" httpUri="http://biocol.org/urn:lsid:biocol.org:col:15536" name="Department of Natural Resources, Environment, The Arts and Sport" pageId="31" pageNumber="32">DNA</collectionCode>
|
||
haplotype diversity (
|
||
<bibRefCitation author="Braulik GT & Barnett R & Odon V & Islas-Villanueva V & Hoelzel AR & Graves JA." box="[1021,1248,1090,1116]" journalOrPublisher="Journal of Mammalian Evolution" pageId="31" pageNumber="32" pagination="111" part="22" refString="Braulik GT, Barnett R, Odon V, Islas-Villanueva V, Hoelzel AR, Graves JA. 2014 b. One species or two? Vicariance, lineage divergence and low mtDNA diversity in geographically isolated populations of South Asian River dolphin. Journal of Mammalian Evolution 22 (1): 111 120." title="One species or two? Vicariance, lineage divergence and low mtDNA diversity in geographically isolated populations of South Asian River dolphin" type="journal article" year="2014" yearSuffix="b">Braulik et al., 2014b</bibRefCitation>
|
||
) places the divergence between subspecies across at around 550,000 years ago (with 95% posterior probability 0.13 1.05 million years ago). The strong ecological disparity between Platanista’ s obligate freshwater lifestyle and the presumed marine lifestyle of all other named platanistoids (
|
||
<figureCitation captionStart="Figure 11" captionStartId="32.[507,571,910,932]" captionTargetBox="[491,1541,229,865]" captionTargetId="figure@32.[491,1541,229,865]" captionTargetPageId="32" captionText="Figure 11 Phylogenetic results of Platanistoidea and major odontocete groups, calibrated for geologic time. Time calibrated phylogenetic tree of the Platanistoidea, pruned from the consensus cladogram in Fig. 10. The groups ‘ stem Odontoceti’ and ‘ all other Odontoceti’ were left as collapsed outgroups. Stratigraphic range data were derived from published accounts for each taxon, including global ranges. Geologic time scale based on Cohen et al. (2013). Stem Odontoceti node depth follows mean divergence date estimates by McGowen, Spaulding & Gatesy (2009); all other nodes (Platanistoidea, Allodelphinidae) should be considered graphical heuristics, and do not reflect divergence dates. Thick bars correspond to the stratigraphic ranges of each taxon, with arrows indicating lower confidence in stratigraphic boundaries. Ecological habitat preference (freshwater vs. marine) is indicated by bar colour, and is based on depositional environment or extant habitat. Labelled circles denode nodebased clades. Abbreviations: Aquitan., Aquitanian; H., Holocene; Langh., Langhian; Mess., Messinian; P., Piacenzian; Ple., Pleistocene; Plioc., Pliocene; Serra., Serravallian; Zan., Zanclean." httpUri="https://zenodo.org/record/270224/files/figure.png" pageId="31" pageNumber="32">Fig. 11</figureCitation>
|
||
) implies some kind of differential evolutionary success for this group, with potentially higher extinction rates in Platanistoidea.
|
||
<bibRefCitation author="Fordyce RE & De Muizon C." box="[981,1274,1289,1315]" editor="Mazin JM" journalOrPublisher="Munchen: Pfeil" pageId="31" pageNumber="32" pagination="234" part="169" refString="Fordyce RE, De Muizon C. 2001. Evolutionary history of whales: a review. In: Mazin JM, De Buffrenil V, eds. Secondary adaptation of tetrapods to life in water. Munchen: Pfeil, 169 234." title="Evolutionary history of whales: a review" type="journal article" volumeTitle="Secondary adaptation of tetrapods to life in water" year="2001">Fordyce & Muizon (2001)</bibRefCitation>
|
||
first proposed that competition between platanistoids and early delphinioids may explain the strong difference in taxonomic richness observed in their fossil records, but this suggestion has never been tested in a rigorous framework (
|
||
<bibRefCitation author="Fordyce RE." box="[869,1025,1409,1435]" editor="Prothero DR" journalOrPublisher="New York: Columbia University Press" pageId="31" pageNumber="32" refString="Fordyce RE. 2003. Cetacea evolution and Eocene-Oligocene ocean revisited. In: Prothero DR, Ivany LC, Nesbitt E, eds. From greenhouse to icehouse: the marine Eocene- Oligocene transition. New York: Columbia University Press." title="Cetacea evolution and Eocene-Oligocene ocean revisited" type="book" volumeTitle="From greenhouse to icehouse: the marine Eocene- Oligocene transition" year="2003">Fordyce, 2003</bibRefCitation>
|
||
;
|
||
<bibRefCitation author="Marx FG & Lambert O & Uhen MD." box="[1039,1378,1409,1435]" journalOrPublisher="Oxford: John Wiley & Sons" pageId="31" pageNumber="32" refString="Marx FG, Lambert O, Uhen MD. 2016. Cetacean paleobiology. Oxford: John Wiley & Sons." title="Cetacean paleobiology" type="book" year="2016">Marx, Lambert & Uhen, 2016</bibRefCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="31.[491,1542,688,1913]" pageId="31" pageNumber="32">
|
||
Platanistoids first appear in the fossil record in the late Oligocene, and reach peak richness in the early Miocene (
|
||
<bibRefCitation author="Kimura T & Barnes LG." box="[860,1129,1488,1514]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="31" pageNumber="32" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes, 2016</bibRefCitation>
|
||
;
|
||
<bibRefCitation author="Tanaka Y & Fordyce RE." box="[1145,1436,1488,1514]" journalOrPublisher="Palaeontologia Electronica" pageId="31" pageNumber="32" pagination="1" part="18" refString="Tanaka Y, Fordyce RE. 2015 a. A new Oligo-Miocene dolphin from New Zealand: Otekaikea huata expands diversity of the early Platanistoidea. Palaeontologia Electronica 18 (2.23 A): 1 71." title="A new Oligo-Miocene dolphin from New Zealand: Otekaikea huata expands diversity of the early Platanistoidea" type="journal article" year="2015" yearSuffix="a">Tanaka & Fordyce, 2015a</bibRefCitation>
|
||
). The oldest platanistoids with solid age constraints are the waipatiids, all found in the Oligocene Miocene Otekaike Limestone of
|
||
<collectingCountry box="[865,1018,1568,1594]" name="New Zealand" pageId="31" pageNumber="32">
|
||
New
|
||
<collectingRegion box="[924,1018,1568,1594]" country="Denmark" name="Sjaelland" pageId="31" pageNumber="32">Zealand</collectingRegion>
|
||
</collectingCountry>
|
||
(
|
||
<bibRefCitation author="Graham IJ & Morgans H & Waghorn DB & Trotter JA & Whitford DJ." box="[1034,1259,1568,1594]" journalOrPublisher="New Zealand Journal of Geology and Geophysics" pageId="31" pageNumber="32" pagination="335" part="43" publicationUrl="10.1080/00288306.2000.9514891." refString="Graham IJ, Morgans H, Waghorn DB, Trotter JA, Whitford DJ. 2000. Strontium isotope stratigraphy of the Oligocene Miocene Otekaike Limestone (Trig Z section) in southern New Zealand: age of the Duntroonian / Waitakian Stage boundary. New Zealand Journal of Geology and Geophysics 43 (3): 335 347 DOI 10.1080 / 00288306.2000.9514891." title="Strontium isotope stratigraphy of the Oligocene Miocene Otekaike Limestone (Trig Z section) in southern New Zealand: age of the Duntroonian / Waitakian Stage boundary" type="journal article" year="2000">Graham et al., 2000</bibRefCitation>
|
||
;
|
||
<bibRefCitation author="Benham WB." box="[1272,1435,1568,1594]" journalOrPublisher="Transactions of the Royal Society of New Zealand" pageId="31" pageNumber="32" pagination="239" part="65" refString="Benham WB. 1935. The teeth of an extinct whale, Microcetus hectori n. sp. Transactions of the Royal Society of New Zealand 65: 239 243." title="The teeth of an extinct whale, Microcetus hectori n. sp" type="journal article" year="1935">Benham, 1935</bibRefCitation>
|
||
;
|
||
<bibRefCitation author="Fordyce RE." editor="Berta A" journalOrPublisher="Proceedings of the San Diego Society of Natural History" pageId="31" pageNumber="32" pagination="147" part="29" refString="Fordyce RE. 1994. Waipatia maerewhenua. 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, vol. 29. San Diego, 147 176." title="Waipatia maerewhenua. New genus and new species (Waipatiidae, New Family), an archaic late oligocene dolphin (Cetacea: Odontoceti: Platanistoidea) from New Zealand" type="journal article" volumeTitle="Contributions in marine mammal Paleontology honoring Frank C. Whitmore, Jr" year="1994">Fordyce, 1994</bibRefCitation>
|
||
;
|
||
<bibRefCitation author="Tanaka Y & Fordyce RE." box="[560,839,1608,1634]" journalOrPublisher="PLoS ONE" pageId="31" pageNumber="32" pagination="9" part="9" publicationUrl="10.1371/journal.pone.0107972." 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 (9): e 107972 DOI 10.1371 / journal. pone. 0107972." title="Fossil Dolphin Otekaikea marplesi (Latest Oligocene, New Zealand) expands the morphological and taxonomic diversity of Oligocene Cetaceans" type="journal article" year="2014">Tanaka & Fordyce, 2014</bibRefCitation>
|
||
;
|
||
<bibRefCitation author="Tanaka Y & Fordyce RE." box="[852,1144,1608,1634]" journalOrPublisher="Palaeontologia Electronica" pageId="31" pageNumber="32" pagination="1" part="18" refString="Tanaka Y, Fordyce RE. 2015 a. A new Oligo-Miocene dolphin from New Zealand: Otekaikea huata expands diversity of the early Platanistoidea. Palaeontologia Electronica 18 (2.23 A): 1 71." title="A new Oligo-Miocene dolphin from New Zealand: Otekaikea huata expands diversity of the early Platanistoidea" type="journal article" year="2015" yearSuffix="a">Tanaka & Fordyce, 2015a</bibRefCitation>
|
||
). Based on both the lithology and the presence of agediagnostic planktic foraminifera and ostracod species, Waipatia hectori (
|
||
<bibRefCitation author="Benham WB." box="[502,665,1687,1713]" journalOrPublisher="Transactions of the Royal Society of New Zealand" pageId="31" pageNumber="32" pagination="239" part="65" refString="Benham WB. 1935. The teeth of an extinct whale, Microcetus hectori n. sp. Transactions of the Royal Society of New Zealand 65: 239 243." title="The teeth of an extinct whale, Microcetus hectori n. sp" type="journal article" year="1935">Benham, 1935</bibRefCitation>
|
||
) is the oldest reported waipatiid, from the uppermost Duntroonian Stage of the Otekaike Limestone, approximately 25.2 Ma (
|
||
<bibRefCitation author="Tanaka, Fordyce RE" box="[1105,1397,1727,1753]" journalOrPublisher="Journal of the Royal Society of New Zealand" pageId="31" pageNumber="32" pagination="135" part="45" publicationUrl="10.1080/03036758.2015.1016046." refString="Tanaka, Fordyce RE. 2015 b. Historically significant late Oligocene dolphin Microcetus hectori Benham 1935: a new species of Waipatia (Platanistoidea). Journal of the Royal Society of New Zealand 45 (3): 135 150 DOI 10.1080 / 03036758.2015.1016046." title="Historically significant late Oligocene dolphin Microcetus hectori Benham 1935: a new species of Waipatia (Platanistoidea)" type="journal article" year="2015" yearSuffix="b">Tanaka & Fordyce, 2015b</bibRefCitation>
|
||
). Arktocara is possibly very similar in age to Waipatia hectori, constrained to the Chattian Stage of the upper Oligocene in the Poul Creek Formation, approximately 24 29 Ma (
|
||
<bibRefCitation author="Perry SE & Garver JI & Ridgway KD." journalOrPublisher="The Journal of Geology" pageId="31" pageNumber="32" pagination="156" part="117" publicationUrl="10.1086/596302." refString="Perry SE, Garver JI, Ridgway KD. 2009. Transport of the Yakutat Terrane, southern Alaska: evidence from sediment petrology and detrital zircon fission-track and U / Pb double dating. The Journal of Geology 117: 156 173 DOI 10.1086 / 596302." title="Transport of the Yakutat Terrane, southern Alaska: evidence from sediment petrology and detrital zircon fission-track and U / Pb double dating" type="journal article" year="2009">Perry, Garver & Ridgway, 2009</bibRefCitation>
|
||
). Unfortunately, the lack of robust locality data for either Waipatia hectori or Arktocara makes impossible to determine which is the oldest.
|
||
</paragraph>
|
||
<caption httpUri="https://zenodo.org/record/270223/files/figure.png" pageId="32" pageNumber="33" targetBox="[491,1541,229,865]" targetPageId="32">
|
||
<caption httpUri="https://zenodo.org/record/270224/files/figure.png" pageId="32" pageNumber="33" targetBox="[491,1541,229,865]" targetPageId="32">
|
||
<paragraph blockId="32.[507,1518,910,1254]" pageId="32" pageNumber="33">
|
||
Figure 11 Phylogenetic results of Platanistoidea and major odontocete groups, calibrated for geologic time. Time calibrated phylogenetic tree of the Platanistoidea, pruned from the consensus cladogram in Fig. 10. The groups ‘stem Odontoceti’ and ‘all other Odontoceti’ were left as collapsed outgroups. Stratigraphic range data were derived from published accounts for each taxon, including global ranges. Geologic time scale based on Cohen et al. (2013). Stem Odontoceti node depth follows mean divergence date estimates by McGowen, Spaulding & Gatesy (2009); all other nodes (Platanistoidea,
|
||
<taxonomicName box="[1346,1501,1056,1078]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="32" pageNumber="33" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
|
||
) should be considered graphical heuristics, and do not reflect divergence dates. Thick bars correspond to the stratigraphic ranges of each taxon, with arrows indicating lower confidence in stratigraphic
|
||
</paragraph>
|
||
</caption>
|
||
<paragraph blockId="32.[507,1518,910,1254]" pageId="32" pageNumber="33">boundaries. Ecological habitat preference (freshwater vs. marine) is indicated by bar colour, and is based on depositional environment or extant habitat. Labelled circles denode nodebased clades. Abbreviations: Aquitan., Aquitanian; H., Holocene; Langh., Langhian; Mess., Messinian; P., Piacenzian; Ple., Pleistocene; Plioc., Pliocene; Serra., Serravallian; Zan., Zanclean.</paragraph>
|
||
</caption>
|
||
<paragraph blockId="32.[491,1541,1305,1849]" pageId="32" pageNumber="33">
|
||
Arktocara is, however, very clearly the oldest known allodelphinid, expanding the previously reported age range of
|
||
<taxonomicName box="[879,1065,1345,1371]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="32" pageNumber="33" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
|
||
by as much as 9 million years (
|
||
<bibRefCitation author="Kimura T & Barnes LG." journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="32" pageNumber="33" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes, 2016</bibRefCitation>
|
||
). Other allodelphinids span temporally from the early to middle Miocene, which largely matches the stratigraphic range of other platanistoid lineages (
|
||
<figureCitation box="[1404,1484,1425,1451]" captionStart="Figure 11" captionStartId="32.[507,571,910,932]" captionTargetBox="[491,1541,229,865]" captionTargetId="figure@32.[491,1541,229,865]" captionTargetPageId="32" captionText="Figure 11 Phylogenetic results of Platanistoidea and major odontocete groups, calibrated for geologic time. Time calibrated phylogenetic tree of the Platanistoidea, pruned from the consensus cladogram in Fig. 10. The groups ‘ stem Odontoceti’ and ‘ all other Odontoceti’ were left as collapsed outgroups. Stratigraphic range data were derived from published accounts for each taxon, including global ranges. Geologic time scale based on Cohen et al. (2013). Stem Odontoceti node depth follows mean divergence date estimates by McGowen, Spaulding & Gatesy (2009); all other nodes (Platanistoidea, Allodelphinidae) should be considered graphical heuristics, and do not reflect divergence dates. Thick bars correspond to the stratigraphic ranges of each taxon, with arrows indicating lower confidence in stratigraphic boundaries. Ecological habitat preference (freshwater vs. marine) is indicated by bar colour, and is based on depositional environment or extant habitat. Labelled circles denode nodebased clades. Abbreviations: Aquitan., Aquitanian; H., Holocene; Langh., Langhian; Mess., Messinian; P., Piacenzian; Ple., Pleistocene; Plioc., Pliocene; Serra., Serravallian; Zan., Zanclean." httpUri="https://zenodo.org/record/270224/files/figure.png" pageId="32" pageNumber="33">Fig. 11</figureCitation>
|
||
). Interestingly, Arktocara is among the oldest crown Odontoceti, reinforcing the longstanding view that the timing for the diversification for crown lineages must have occurred no later than the early Oligocene.
|
||
</paragraph>
|
||
<paragraph blockId="32.[491,1541,1305,1849]" pageId="32" pageNumber="33">
|
||
Lastly,
|
||
<taxonomicName box="[605,791,1584,1610]" class="Mammalia" family="Allodelphinidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cetacea" pageId="32" pageNumber="33" phylum="Chordata" rank="family">Allodelphinidae</taxonomicName>
|
||
appear uniquely limited, in terms of geography, to marine rocks of the North Pacific Ocean, with occurrences in
|
||
<collectingCountry box="[1054,1123,1624,1650]" name="Japan" pageId="32" pageNumber="33">Japan</collectingCountry>
|
||
,
|
||
<collectingRegion box="[1135,1214,1624,1650]" country="United States of America" name="Alaska" pageId="32" pageNumber="33">Alaska</collectingRegion>
|
||
,
|
||
<collectingRegion box="[1225,1368,1624,1650]" country="United States of America" name="Washington" pageId="32" pageNumber="33">Washington</collectingRegion>
|
||
State,
|
||
<collectingRegion box="[1446,1537,1624,1650]" country="United States of America" name="Oregon" pageId="32" pageNumber="33">Oregon</collectingRegion>
|
||
, and
|
||
<collectingRegion box="[544,662,1664,1690]" country="United States of America" name="California" pageId="32" pageNumber="33">California</collectingRegion>
|
||
(see
|
||
<figureCitation box="[724,804,1664,1690]" captionStart="Figure 12" captionStartId="33.[507,571,751,773]" captionTargetBox="[491,1541,229,706]" captionTargetId="figure@33.[491,1541,229,706]" captionTargetPageId="33" captionText="Figure 12 Distribution map of fossil Allodelphinidae. Mapped of fossil localities of allodelphinids, projected on a truncated Winkel Tripel map and centered on 25 N and 170 W. Occurrences for fossil data derive from location of type and referred localities for each taxon, are listed alphabetically by region, and are represented by orange dots." httpUri="https://zenodo.org/record/270225/files/figure.png" pageId="32" pageNumber="33">Fig. 12</figureCitation>
|
||
;
|
||
<bibRefCitation author="Kimura T & Barnes LG." box="[819,1088,1664,1690]" journalOrPublisher="Bulletin of the Gunma Museum of Natural History" pageId="32" pageNumber="33" pagination="1" part="20" refString="Kimura T, Barnes LG. 2016. New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean. Bulletin of the Gunma Museum of Natural History 20: 1 58." title="New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean" type="journal article" year="2016">Kimura & Barnes, 2016</bibRefCitation>
|
||
). Arktocara expands this geographic range to subArctic latitudes. At approximately 60 N in the Yakutat City and Borough, Arktocara is the most northern platanistoid yet reported. The next most northern platanistoid reported is an incomplete and unnamed specimen from the late Chattian marine Vejle Fjord Formation in northern
|
||
<collectingCountry box="[906,1020,1823,1849]" name="Denmark" pageId="32" pageNumber="33">Denmark</collectingCountry>
|
||
, approximately
|
||
<geoCoordinate box="[1208,1293,1823,1849]" direction="north" orientation="latitude" pageId="32" pageNumber="33" precision="5555" value="56.7">56.7 N</geoCoordinate>
|
||
,
|
||
<geoCoordinate box="[1305,1368,1823,1849]" direction="east" orientation="longitude" pageId="32" pageNumber="33" precision="5555" value="9.0">9.0 E</geoCoordinate>
|
||
(
|
||
<bibRefCitation author="Hoch E." box="[1386,1515,1823,1849]" journalOrPublisher="Historical Biology" pageId="32" pageNumber="33" pagination="670" part="14" refString="Hoch E. 2000. Olfaction in whales: evidence from a young odontocete of the Late Oligocene North Sea. Historical Biology 14: 670 689." title="Olfaction in whales: evidence from a young odontocete of the Late Oligocene North Sea" type="journal article" year="2000">Hoch, 2000</bibRefCitation>
|
||
).
|
||
</paragraph>
|
||
</subSubSection>
|
||
</treatment>
|
||
</document> |