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<taxonomicName id="10ED4D39FF8FFF8DFDCD7BB9FBC77EA3" authority="Aubrechtova, 2015" authorityName="Aubrechtova" authorityYear="2015" box="[539,1049,1196,1223]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="35" pageNumber="36" phylum="Mollusca" rank="species" species="boliviensis">
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<bibRefCitation id="B37C4B4BFF8FFF8DFCEE7BB9FBC77EA3" author="Aubrechtova M." box="[824,1049,1196,1223]" pageId="35" pageNumber="36" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová, 2015</bibRefCitation>
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<paragraph id="D75236BAFF8FFF8DFDFF7BC4FBD57E8E" blockId="35.[539,1049,1196,1258]" box="[553,1035,1232,1258]" pageId="35" pageNumber="36">
<figureCitation id="4FD62A3FFF8FFF8DFDFF7BC4FD0D7E8E" box="[553,723,1232,1258]" captionStart="Fig" captionStartId="22.[189,232,1536,1562]" captionTargetId="figure-11@21.[189,1398,272,2011]" captionTargetPageId="21" captionText="Fig. 12 (previous page). Apical parts of orthoconic cephalopods from the Olenidsletta Member, Floian, Ordovician, near Hinlopenstretet, Ny Friesland, Spitsbergen. A. Cyptendoceras sp. B., FMNH-P30472 from Profilbekken river basin, locality PR-phosphatic. Lateral view with siphuncle toward the left. B. Svalbardoceras sterna gen. et sp. nov, FMNH-P30169, from PO 7.5. Lateral view with siphuncle toward left. C, F–G. Eosomichelinoceras borealis sp. nov. C. Specimen FMNH-P30171, from bed PO 123.3. Lateral view with prosiphuncular side toward the right. D. Bactroceras fluvii sp. nov., FMNH-P30168, from Profilbekken river basin, locality PR-phosphatic, showing the ventral side with ventral sutural lobe. E, H, J. Bactroceras boliviensis Aubrechtová, 2015 from bed PO 131. E. Specimen FMNH-P30165, nearly dorsal view, showing the transition of the extreme apical part toward the juvenile part of the conch. F. Specimen FMNH-P30182, lateral view with siphuncle toward the right. G. Specimen FMNH-P30184, lateral view with siphuncle toward the left. H. Specimen FMNH-P30183, apical view, showing the smooth apical surface of the protoconch. I. Ethanoceras solitudines gen. et sp. nov., FMNH-P30173, from bed PO 123.3, note the fine transverse striation. J. FMNH-P30160, showing details of fine transverse ornamentation. Scale bar = 2 mm for all figures." figureDoi="http://doi.org/10.5281/zenodo.5794307" httpUri="https://zenodo.org/record/5794307/files/figure.png" pageId="35" pageNumber="36">Figs 12E, H, J</figureCitation>
, 
<figureCitation id="4FD62A3FFF8FFF8DFD097BC4FCCC7E8E" box="[735,786,1232,1258]" captionStart="Fig" captionStartId="23.[189,232,1812,1838]" captionTargetBox="[201,1394,1216,1772]" captionTargetId="figure-239@23.[189,1398,1216,1772]" captionTargetPageId="23" captionText="Fig. 13. Details of the conch surface of transversally ornamented orthocones from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A. Ethanoceras solitudines gen. et sp. nov., FMNH-P30383, holotype, from bed PO 131. B. Eosomichelinoceras borealis sp. nov., FMNH-P30279, holotype, from bed PO 123.3. C. Bactroceras boliviensis Aubrechtová, 2015, FMNH-P30232, from bed PO 131, conch section with nearly cyclic spacing of transverse striae. Scale bar = 10 mm for all figures." figureDoi="http://doi.org/10.5281/zenodo.5793460" httpUri="https://zenodo.org/record/5793460/files/figure.png" pageId="35" pageNumber="36">13C</figureCitation>
, 
<figureCitation id="4FD62A3FFF8FFF8DFCC87BC4FCB57E8E" box="[798,875,1232,1258]" captionStart-0="Fig" captionStart-1="Fig" captionStart-2="Fig" captionStart-3="Fig" captionStartId-0="35.[189,232,1880,1906]" captionStartId-1="36.[190,233,1778,1804]" captionStartId-2="37.[188,231,1882,1908]" captionStartId-3="38.[190,233,1852,1878]" captionTargetBox-0="[204,1395,1485,1808]" captionTargetBox-1="[193,1396,909,1740]" captionTargetBox-2="[388,1203,1512,1836]" captionTargetBox-3="[196,1394,551,1812]" captionTargetId-0="figure-405@35.[189,1398,1475,1815]" captionTargetId-1="figure-178@36.[189,1398,909,1740]" captionTargetId-2="figure-494@37.[375,1213,1504,1844]" captionTargetId-3="figure-73@38.[189,1398,551,1812]" captionTargetPageId-0="35" captionTargetPageId-1="36" captionTargetPageId-2="37" captionTargetPageId-3="38" captionText-0="Fig. 24. Diagrams of spacing of ornamentation, angle of expansion, and relative chamber length of Bactroceras boliviensis Aubrechtová, 2015 from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimens from Aubrechtová (2015). See Supp. file 1 for details of measurements." captionText-1="Fig. 25. Bactroceras boliviensis Aubrechtová, 2015, from bed PO 131, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A. Specimen FMNH-P30430, lateral view of body chamber with dorsomyarian muscle impression at base ventral, prosiphuncular side toward the left. B. Specimen FMNH-P30231, view of ventral, prosiphuncular side. C. Specimen FMNH-P30248, lateral view of specimen with partly cyclic spacing of ornamentation; ventral, prosiphuncular side toward the right. D. Specimen FMNH-P30215, with fine transverse ornamentation; ventral, prosiphuncular side toward the right. Scale bar = 10 mm for all figures." captionText-2="Fig. 26. Diagrams of relative siphuncular diameter and relative siphuncular distance of Bactroceras boliviensis Aubrechtová, 2015, from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimen from Aubrechtová (2015). See Supp. file 1 for details of measurements." captionText-3="Fig. 27. Median sections of phragmocones of Bactroceras boliviensis Aubrechtová, 2015, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Note conical endisiphuncular lining in A–D. A. Specimen FMNH-P30215, from bed PO 131. B. Specimen FMNH-P30259, from bed PO 7.5. C–D. Specimen FMNH-P30243, from bed PO 7.5. E. Specimen FMNH-P30383, from bed PO 131. Scale bars: A–C, E = 5 mm; D = 1 mm." figureDoi-0="http://doi.org/10.5281/zenodo.5793498" figureDoi-1="http://doi.org/10.5281/zenodo.5793500" figureDoi-2="http://doi.org/10.5281/zenodo.5793502" figureDoi-3="http://doi.org/10.5281/zenodo.5793506" httpUri-0="https://zenodo.org/record/5793498/files/figure.png" httpUri-1="https://zenodo.org/record/5793500/files/figure.png" httpUri-2="https://zenodo.org/record/5793502/files/figure.png" httpUri-3="https://zenodo.org/record/5793506/files/figure.png" pageId="35" pageNumber="36">24–27</figureCitation>
, 
<figureCitation id="4FD62A3FFF8FFF8DFCA07BC4FC107E8E" box="[886,974,1232,1258]" captionStart="Fig" captionStartId="39.[191,234,1845,1871]" captionTargetBox="[195,1392,1361,1805]" captionTargetId="figure-432@39.[189,1398,1339,1807]" captionTargetPageId="39" captionText="Fig. 28.Reconstructionand interpretation of detailsof connecting ring and septal necks.A–B. Bactroceras boliviensisAubrechtová, 2015.A. Specimen FMNH-P30243, see Fig. 27D.B. Specimen FMNH-P30215, see Fig.29A.C. Eosomichelinoceras borealis sp. nov., from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen, specimen FMNH-P30305, see Fig. 33C. Black: septal neck and septum. Dark grey: connecting ring. Light grey: endosiphuncular deposits. Without scale." figureDoi="http://doi.org/10.5281/zenodo.5793508" httpUri="https://zenodo.org/record/5793508/files/figure.png" pageId="35" pageNumber="36">28A–B</figureCitation>
, 
<figureCitation id="4FD62A3FFF8FFF8DFC0C7BC4FBD57E8E" box="[986,1035,1232,1258]" captionStart="Fig" captionStartId="40.[189,232,1780,1806]" captionTargetBox="[369,1217,265,1736]" captionTargetId="figure-13@40.[369,1218,265,1743]" captionTargetPageId="40" captionText="Fig. 29. Median sections of phragmocones of Bactroceras Holm, 1898. A, C–D. Bactroceras fluvii sp. nov., from Profilbekken river basin, locality PR-phosphatic. A. Specimen FMNH-P30159, with adapical siphuncular segment, taphonomically slightly distorted.B. Bactroceras boliviensisAubrechtová, 2015, FMNH-P30176 from bed PO 131, extreme apical part. C–D. Specimen FMNH-P30177, holotype. C. Details of the protoconch. D. Apical part with transition toward juvenile growth stages; note the slightly expanded siphuncular segments. Scale bars: A = 5 mm; B–C = 1 mm; D = 2 mm." figureDoi="http://doi.org/10.5281/zenodo.5793512" httpUri="https://zenodo.org/record/5793512/files/figure.png" pageId="35" pageNumber="36">29B</figureCitation>
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<emphasis id="E599EAA8FF8FFF8DFF6B7A06FE0E7F4F" box="[189,464,1297,1323]" italics="true" pageId="35" pageNumber="36">Bactroceras boliviensis</emphasis>
<bibRefCitation id="B37C4B4BFF8FFF8DFE007A05FCEE7F4F" author="Aubrechtova M." box="[470,816,1297,1324]" pageId="35" pageNumber="36" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová, 2015: 206–207</bibRefCitation>
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, fig. 6a–d, g.
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<emphasis id="E599EAA8FF8FFF8DFF6B7A40FE957F09" box="[189,331,1364,1389]" italics="true" pageId="35" pageNumber="36">Bactroceras</emphasis>
aff. 
<emphasis id="E599EAA8FF8FFF8DFE577A40FE697F09" box="[385,439,1364,1389]" italics="true" pageId="35" pageNumber="36">avus</emphasis>
Holm
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– 
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<bibRefCitation id="B37C4B4BFF8FFF8DFDC97A47FCFE7F0A" author="Marek J. &amp; Weber B. &amp; Schonian F. &amp; Egenhoff S. O. &amp; Erdtmann D." box="[543,800,1363,1390]" pageId="35" pageNumber="36" pagination="56" refId="ref49002" refString="Marek J., Weber B., Schonian F., Egenhoff S. O. &amp; Erdtmann D. 2000. Arenig cephalopods from Bolivia. In: Cockle P., Wilson G., Brock G., Engelbretsen M., Simpson A. &amp; Winchester-Seeto T. (eds) Palaeontology Down Under 2000, Geological Society of Australia, Abstracts: 56. Geological Society of Australia, Sydney." type="book chapter" year="2000">
Marek 
<emphasis id="E599EAA8FF8FFF8DFDA47A40FD737F09" box="[626,685,1363,1389]" italics="true" pageId="35" pageNumber="36">et al.</emphasis>
2000: 56
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<emphasis id="E599EAA8FF8FFF8DFF6B7A63FDFA7FF4" box="[189,548,1398,1424]" italics="true" pageId="35" pageNumber="36">Bactroceras angustisiphonatum</emphasis>
(Rüdiger)
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– 
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<bibRefCitation id="B37C4B4BFF8FFF8DFD657A62FC517FF4" author="Evans D. H." box="[691,911,1398,1425]" pageId="35" pageNumber="36" pagination="1 - 81" refId="ref46068" refString="Evans D. H. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 628: 1 - 81." type="journal article" year="2005">Evans 2005: 27–31</bibRefCitation>
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, pl. 3 figs 12–13, 15, 17–18, pl. 4 figs 2, 16.
</treatmentCitationGroup>
</paragraph>
</subSubSection>
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<emphasis id="E599EAA8FF8FFF8DFF6B784CFEC07D16" bold="true" box="[189,286,1880,1906]" pageId="35" pageNumber="36">Fig. 24.</emphasis>
Diagrams of spacing of ornamentation, angle of expansion, and relative chamber length of 
<taxonomicName id="10ED4D39FF8FFF8DFF6B7869FD0D7DF3" authority="Aubrechtova, 2015" authorityName="Aubrechtova" authorityYear="2015" box="[189,723,1916,1943]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="35" pageNumber="36" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8FFF8DFF6B7869FE077DF2" box="[189,473,1916,1942]" italics="true" pageId="35" pageNumber="36">Bactroceras boliviensis</emphasis>
<bibRefCitation id="B37C4B4BFF8FFF8DFE3F7868FD0D7DF3" author="Aubrechtova M." box="[489,723,1916,1943]" pageId="35" pageNumber="36" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová, 2015</bibRefCitation>
</taxonomicName>
from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimens from 
<bibRefCitation id="B37C4B4BFF8FFF8DFB09788BFED17DB9" author="Aubrechtova M." pageId="35" pageNumber="36" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová (2015)</bibRefCitation>
. See Supp. file 1 for details of measurements.
</paragraph>
</caption>
<subSubSection id="9FF76531FF88FF8AFF6B7E1CFC4C7BFC" pageId="36" pageNumber="37" type="diagnosis">
<paragraph id="D75236BAFF88FF8AFF6B7E1CFEE87B46" blockId="36.[189,310,264,290]" box="[189,310,264,290]" pageId="36" pageNumber="37">
<heading id="8C1A81D6FF88FF8AFF6B7E1CFEE87B46" bold="true" box="[189,310,264,290]" fontSize="11" level="3" pageId="36" pageNumber="37" reason="3">
<emphasis id="E599EAA8FF88FF8AFF6B7E1CFEE87B46" bold="true" box="[189,310,264,290]" pageId="36" pageNumber="37">Diagnosis</emphasis>
</heading>
</paragraph>
<paragraph id="D75236BAFF88FF8AFF6B7E2CFC4C7BFC" blockId="36.[187,1398,311,408]" pageId="36" pageNumber="37">
<taxonomicName id="10ED4D39FF88FF8AFF6B7E2CFE957B35" authorityName="Holm" authorityYear="1898" box="[189,331,312,337]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="36" pageNumber="37" phylum="Mollusca" rank="genus">
<emphasis id="E599EAA8FF88FF8AFF6B7E2CFE957B35" box="[189,331,312,337]" italics="true" pageId="36" pageNumber="37">Bactroceras</emphasis>
</taxonomicName>
with a large shell diameter (&gt; 
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), ornamented with transverse striae, and with concavity of septa of 30%; siphuncle tubular, marginal; diameter of siphuncle ⅛ to ¹/7 of the corresponding conch diameter; connecting ring very thin (after 
<bibRefCitation id="B37C4B4BFF88FF8AFD717E69FC587BFC" author="Aubrechtova M." box="[679,902,381,408]" pageId="36" pageNumber="37" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová 2015</bibRefCitation>
).
</paragraph>
</subSubSection>
<subSubSection id="9FF76531FF88FF8AFF6B7EABFD767815" pageId="36" pageNumber="37" type="materials_examined">
<paragraph id="D75236BAFF88FF8AFF6B7EABFE747BBD" blockId="36.[189,426,447,473]" box="[189,426,447,473]" pageId="36" pageNumber="37">
<heading id="8C1A81D6FF88FF8AFF6B7EABFE747BBD" bold="true" box="[189,426,447,473]" fontSize="11" level="3" pageId="36" pageNumber="37" reason="3">
<emphasis id="E599EAA8FF88FF8AFF6B7EABFE747BBD" bold="true" box="[189,426,447,473]" pageId="36" pageNumber="37">Material examined</emphasis>
</heading>
</paragraph>
<paragraph id="D75236BAFF88FF8AFF6B7EF9FD767815" blockId="36.[189,1398,493,625]" pageId="36" pageNumber="37">
<materialsCitation id="67853CE7FF88FF8AFF6B7EF9FBF6782A" ID-GBIF-Occurrence="3991621302" collectionCode="PO" location="one from bed PO 7" pageId="36" pageNumber="37" specimenCount="1">
<specimenCount id="C1EBFD33FF88FF8AFF6B7EF9FE187863" box="[189,454,493,519]" pageId="36" pageNumber="37" type="generic">Sixty-eight specimens</specimenCount>
(see Supp. file 1 for list of specimens); one from bed PO 7, two from bed PO 7.5, two from bed PO 123.3, and 62 from bed PO 131, 
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, 
<quantity id="10159B5FFF88FF8AFC0E7D04FBFE784F" box="[984,1056,528,555]" metricMagnitude="0" metricUnit="m" metricValue="4.5" pageId="36" pageNumber="37" unit="m" value="4.5">4.5 m</quantity>
, 
<quantity id="10159B5FFF88FF8AFBE67D05FB4B784F" box="[1072,1173,529,555]" metricMagnitude="2" metricUnit="m" metricValue="1.2029999999999998" pageId="36" pageNumber="37" unit="m" value="120.3">120.3 m</quantity>
, and 
<quantity id="10159B5FFF88FF8AFB0F7D05FAF8784F" box="[1241,1318,529,555]" metricMagnitude="2" metricUnit="m" metricValue="1.28" pageId="36" pageNumber="37" unit="m" value="128.0">128 m</quantity>
above base of Olenidsletta Member, V1–V2 trilobite zone, Blackhillsian, Floian.
</materialsCitation>
<materialsCitation id="67853CE7FF88FF8AFBF87D20FD767815" ID-GBIF-Occurrence="3991621301" collectionCode="PO" location="one from bed PO 7" pageId="36" pageNumber="37" specimenCount="15">
An additional number of 
<specimenCount id="C1EBFD33FF88FF8AFA8F7D20FE107815" pageId="36" pageNumber="37">15 microscopic specimens</specimenCount>
from bed PO 131.
</materialsCitation>
</paragraph>
</subSubSection>
<subSubSection id="9FF76531FF88FF88FF6B7D8CFC0F7B22" lastPageId="38" lastPageNumber="39" pageId="36" pageNumber="37" type="description">
<paragraph id="D75236BAFF88FF8AFF6B7D8CFE9078D6" blockId="36.[189,334,664,690]" box="[189,334,664,690]" pageId="36" pageNumber="37">
<heading id="8C1A81D6FF88FF8AFF6B7D8CFE9078D6" bold="true" box="[189,334,664,690]" fontSize="11" level="3" pageId="36" pageNumber="37" reason="3">
<emphasis id="E599EAA8FF88FF8AFF6B7D8CFE9078D6" bold="true" box="[189,334,664,690]" pageId="36" pageNumber="37">Description</emphasis>
</heading>
</paragraph>
<paragraph id="D75236BAFF88FF8AFF6B7DD3FAAB7943" blockId="36.[188,1399,710,808]" pageId="36" pageNumber="37">
The conchs are straight and expand gradually with a low angle of expansion, ca 4° (mean 3.7°; 1 
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–3 
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quantile: 2.7–4.5; n = 37) (
<figureCitation id="4FD62A3FFF88FF8AFE257DFEFD947960" box="[499,586,746,772]" captionStart="Fig" captionStartId="35.[189,232,1880,1906]" captionTargetBox="[204,1395,1485,1808]" captionTargetId="figure-405@35.[189,1398,1475,1815]" captionTargetPageId="35" captionText="Fig. 24. Diagrams of spacing of ornamentation, angle of expansion, and relative chamber length of Bactroceras boliviensis Aubrechtová, 2015 from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimens from Aubrechtová (2015). See Supp. file 1 for details of measurements." figureDoi="http://doi.org/10.5281/zenodo.5793498" httpUri="https://zenodo.org/record/5793498/files/figure.png" pageId="36" pageNumber="37">Fig. 24</figureCitation>
). The conch cross section is invariantly circular. The largest specimen in the sample is a fragmentary body chamber with a maximum diameter of ca 
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and a length of
</paragraph>
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<paragraph id="D75236BAFF88FF8AFF6879E6FBBE7D84" blockId="36.[189,1399,1778,2016]" pageId="36" pageNumber="37">
<emphasis id="E599EAA8FF88FF8AFF6879E6FEC37D68" bold="true" box="[190,285,1778,1804]" pageId="36" pageNumber="37">Fig. 25.</emphasis>
<taxonomicName id="10ED4D39FF88FF8AFEF279E7FCFC7D69" authority="Aubrechtova, 2015" authorityName="Aubrechtova" authorityYear="2015" box="[292,802,1778,1805]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF88FF8AFEF279E7FDE87D69" box="[292,566,1779,1805]" italics="true" pageId="36" pageNumber="37">Bactroceras boliviensis</emphasis>
<bibRefCitation id="B37C4B4BFF88FF8AFDEB79E7FCFC7D69" author="Aubrechtova M." box="[573,802,1778,1805]" pageId="36" pageNumber="37" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová, 2015</bibRefCitation>
</taxonomicName>
, from bed PO 131, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. 
<emphasis id="E599EAA8FF88FF8AFBDB7802FBFC7D54" bold="true" box="[1037,1058,1814,1840]" pageId="36" pageNumber="37">A</emphasis>
. Specimen FMNH-P30430, lateral view of body chamber with dorsomyarian muscle impression at base ventral, prosiphuncular side toward the left. 
<emphasis id="E599EAA8FF88FF8AFE617848FE177D12" bold="true" box="[439,457,1884,1910]" pageId="36" pageNumber="37">B</emphasis>
. Specimen FMNH-P30231, view of ventral, prosiphuncular side. 
<emphasis id="E599EAA8FF88FF8AFB097848FB2C7D12" bold="true" box="[1247,1266,1884,1910]" pageId="36" pageNumber="37">C</emphasis>
. Specimen FMNH-P30248, lateral view of specimen with partly cyclic spacing of ornamentation; ventral, prosiphuncular side toward the right. 
<emphasis id="E599EAA8FF88FF8AFDA578B7FD567DD9" bold="true" box="[627,648,1955,1981]" pageId="36" pageNumber="37">D</emphasis>
. Specimen FMNH-P30215, with fine transverse ornamentation; ventral, prosiphuncular side toward the right. Scale bar = 10 mm for all figures.
</paragraph>
</caption>
<paragraph id="D75236BAFF89FF8BFF6B7E1DFC657B23" blockId="37.[189,1398,265,327]" pageId="37" pageNumber="38">
<quantity id="10159B5FFF89FF8BFF6B7E1DFECF7B47" box="[189,273,265,291]" metricMagnitude="-2" metricUnit="m" metricValue="9.2" pageId="37" pageNumber="38" unit="mm" value="92.0">92 mm</quantity>
(specimen FMNH-P30179). At the base of the body chamber, where the diameter is 
<quantity id="10159B5FFF89FF8BFAD07E1DFA837B47" box="[1286,1373,265,291]" metricMagnitude="-2" metricUnit="m" metricValue="3.8" pageId="37" pageNumber="38" unit="mm" value="38.0">38 mm</quantity>
, a narrow paired dorsomyarian muscle scar is preserved (
<figureCitation id="4FD62A3FFF89FF8BFC967E38FC707B23" box="[832,942,300,327]" captionStart="Fig" captionStartId="36.[190,233,1778,1804]" captionTargetBox="[193,1396,909,1740]" captionTargetId="figure-178@36.[189,1398,909,1740]" captionTargetPageId="36" captionText="Fig. 25. Bactroceras boliviensis Aubrechtová, 2015, from bed PO 131, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A. Specimen FMNH-P30430, lateral view of body chamber with dorsomyarian muscle impression at base ventral, prosiphuncular side toward the left. B. Specimen FMNH-P30231, view of ventral, prosiphuncular side. C. Specimen FMNH-P30248, lateral view of specimen with partly cyclic spacing of ornamentation; ventral, prosiphuncular side toward the right. D. Specimen FMNH-P30215, with fine transverse ornamentation; ventral, prosiphuncular side toward the right. Scale bar = 10 mm for all figures." figureDoi="http://doi.org/10.5281/zenodo.5793500" httpUri="https://zenodo.org/record/5793500/files/figure.png" pageId="37" pageNumber="38">Fig. 25A</figureCitation>
).
</paragraph>
<paragraph id="D75236BAFF89FF8BFF6B7E7AFE42785C" blockId="37.[188,1399,366,568]" pageId="37" pageNumber="38">
The conch surface is ornamented with striae, which are directly transverse and run parallel to the sutures (
<figureCitation id="4FD62A3FFF89FF8BFF127E85FEE97BCF" box="[196,311,401,427]" captionStart="Fig" captionStartId="23.[189,232,1812,1838]" captionTargetBox="[201,1394,1216,1772]" captionTargetId="figure-239@23.[189,1398,1216,1772]" captionTargetPageId="23" captionText="Fig. 13. Details of the conch surface of transversally ornamented orthocones from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A. Ethanoceras solitudines gen. et sp. nov., FMNH-P30383, holotype, from bed PO 131. B. Eosomichelinoceras borealis sp. nov., FMNH-P30279, holotype, from bed PO 123.3. C. Bactroceras boliviensis Aubrechtová, 2015, FMNH-P30232, from bed PO 131, conch section with nearly cyclic spacing of transverse striae. Scale bar = 10 mm for all figures." figureDoi="http://doi.org/10.5281/zenodo.5793460" httpUri="https://zenodo.org/record/5793460/files/figure.png" pageId="37" pageNumber="38">Figs 13C</figureCitation>
, 
<figureCitation id="4FD62A3FFF89FF8BFE917E85FE7F7BC8" box="[327,417,401,428]" captionStart="Fig" captionStartId="36.[190,233,1778,1804]" captionTargetBox="[193,1396,909,1740]" captionTargetId="figure-178@36.[189,1398,909,1740]" captionTargetPageId="36" captionText="Fig. 25. Bactroceras boliviensis Aubrechtová, 2015, from bed PO 131, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A. Specimen FMNH-P30430, lateral view of body chamber with dorsomyarian muscle impression at base ventral, prosiphuncular side toward the left. B. Specimen FMNH-P30231, view of ventral, prosiphuncular side. C. Specimen FMNH-P30248, lateral view of specimen with partly cyclic spacing of ornamentation; ventral, prosiphuncular side toward the right. D. Specimen FMNH-P30215, with fine transverse ornamentation; ventral, prosiphuncular side toward the right. Scale bar = 10 mm for all figures." figureDoi="http://doi.org/10.5281/zenodo.5793500" httpUri="https://zenodo.org/record/5793500/files/figure.png" pageId="37" pageNumber="38">25B–D</figureCitation>
). The striae are very slightly shifted toward the apex at the prosiphuncular side, forming a very shallow ventral sinus. The striae have partly an imbricated profile in well preserved specimens and are rounded in less well preserved and smaller specimens. The spacing of the striae increases with growth in relation to the conch diameter (
<figureCitation id="4FD62A3FFF89FF8BFC877EEEFC777871" box="[849,937,506,533]" captionStart="Fig" captionStartId="35.[189,232,1880,1906]" captionTargetBox="[204,1395,1485,1808]" captionTargetId="figure-405@35.[189,1398,1475,1815]" captionTargetPageId="35" captionText="Fig. 24. Diagrams of spacing of ornamentation, angle of expansion, and relative chamber length of Bactroceras boliviensis Aubrechtová, 2015 from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimens from Aubrechtová (2015). See Supp. file 1 for details of measurements." figureDoi="http://doi.org/10.5281/zenodo.5793498" httpUri="https://zenodo.org/record/5793498/files/figure.png" pageId="37" pageNumber="38">Fig. 24</figureCitation>
), reaching densities between 1–20 lirae per one millimeter.
</paragraph>
<paragraph id="D75236BAFF89FF8BFF6B7D4BFD207914" blockId="37.[189,1400,607,880]" pageId="37" pageNumber="38">
The relative chamber length varies between 
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the smallest preserved growth stages with diameters of less than 
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and 
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the largest specimens with diameters&gt; 
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. The diameter of the septal foramen is ca ¹/6 of corresponding conch cross section (mean rSD = 0.17; 1 
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–3 
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quantile: 0.15–0.19; n = 55) (
<figureCitation id="4FD62A3FFF89FF8BFEF57DDDFEA47887" box="[291,378,712,739]" captionStart="Fig" captionStartId="37.[188,231,1882,1908]" captionTargetBox="[388,1203,1512,1836]" captionTargetId="figure-494@37.[375,1213,1504,1844]" captionTargetPageId="37" captionText="Fig. 26. Diagrams of relative siphuncular diameter and relative siphuncular distance of Bactroceras boliviensis Aubrechtová, 2015, from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimen from Aubrechtová (2015). See Supp. file 1 for details of measurements." figureDoi="http://doi.org/10.5281/zenodo.5793502" httpUri="https://zenodo.org/record/5793502/files/figure.png" pageId="37" pageNumber="38">Fig. 26</figureCitation>
). The rSD decreases with conch diameter toward 0.15 at a maximum conch diameter of 
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(
<figureCitation id="4FD62A3FFF89FF8BFEF67DF8FEA77963" box="[288,377,748,775]" captionStart="Fig" captionStartId="37.[188,231,1882,1908]" captionTargetBox="[388,1203,1512,1836]" captionTargetId="figure-494@37.[375,1213,1504,1844]" captionTargetPageId="37" captionText="Fig. 26. Diagrams of relative siphuncular diameter and relative siphuncular distance of Bactroceras boliviensis Aubrechtová, 2015, from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimen from Aubrechtová (2015). See Supp. file 1 for details of measurements." figureDoi="http://doi.org/10.5281/zenodo.5793502" httpUri="https://zenodo.org/record/5793502/files/figure.png" pageId="37" pageNumber="38">Fig. 26</figureCitation>
). The siphuncle is eccentric, positioned between the center of the conch and the conch margin in early growth stages with conch cross section diameters &lt;
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, and it is nearly marginal in later growth stages (
<figureCitation id="4FD62A3FFF89FF8BFE617C26FDCC7929" box="[439,530,818,845]" captionStart="Fig" captionStartId="37.[188,231,1882,1908]" captionTargetBox="[388,1203,1512,1836]" captionTargetId="figure-494@37.[375,1213,1504,1844]" captionTargetPageId="37" captionText="Fig. 26. Diagrams of relative siphuncular diameter and relative siphuncular distance of Bactroceras boliviensis Aubrechtová, 2015, from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimen from Aubrechtová (2015). See Supp. file 1 for details of measurements." figureDoi="http://doi.org/10.5281/zenodo.5793502" httpUri="https://zenodo.org/record/5793502/files/figure.png" pageId="37" pageNumber="38">Fig. 26</figureCitation>
). The septal necks are orthochoanitic and the siphuncular segments are tubular and have a thin connecting ring (
<figureCitation id="4FD62A3FFF89FF8BFD4F7C41FD2E7914" box="[665,752,853,880]" captionStart="Fig" captionStartId="38.[190,233,1852,1878]" captionTargetBox="[196,1394,551,1812]" captionTargetId="figure-73@38.[189,1398,551,1812]" captionTargetPageId="38" captionText="Fig. 27. Median sections of phragmocones of Bactroceras boliviensis Aubrechtová, 2015, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Note conical endisiphuncular lining in A–D. A. Specimen FMNH-P30215, from bed PO 131. B. Specimen FMNH-P30259, from bed PO 7.5. C–D. Specimen FMNH-P30243, from bed PO 7.5. E. Specimen FMNH-P30383, from bed PO 131. Scale bars: A–C, E = 5 mm; D = 1 mm." figureDoi="http://doi.org/10.5281/zenodo.5793506" httpUri="https://zenodo.org/record/5793506/files/figure.png" pageId="37" pageNumber="38">Fig. 27</figureCitation>
).
</paragraph>
<paragraph id="D75236BAFF89FF8BFF6B7C83FCFA7E7F" blockId="37.[189,1399,919,1051]" pageId="37" pageNumber="38">
The siphuncles of specimen FMNH-P30215 from bed PO 131, and specimens FMNH-P30243 and FMNH-P30259 from bed PO 7.5 (
<figureCitation id="4FD62A3FFF89FF8BFDA77CAEFCD579B0" box="[625,779,954,980]" captionStart="Fig" captionStartId="38.[190,233,1852,1878]" captionTargetBox="[196,1394,551,1812]" captionTargetId="figure-73@38.[189,1398,551,1812]" captionTargetPageId="38" captionText="Fig. 27. Median sections of phragmocones of Bactroceras boliviensis Aubrechtová, 2015, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Note conical endisiphuncular lining in A–D. A. Specimen FMNH-P30215, from bed PO 131. B. Specimen FMNH-P30259, from bed PO 7.5. C–D. Specimen FMNH-P30243, from bed PO 7.5. E. Specimen FMNH-P30383, from bed PO 131. Scale bars: A–C, E = 5 mm; D = 1 mm." figureDoi="http://doi.org/10.5281/zenodo.5793506" httpUri="https://zenodo.org/record/5793506/files/figure.png" pageId="37" pageNumber="38">Figs 27A–D</figureCitation>
, 
<figureCitation id="4FD62A3FFF89FF8BFCC87CAEFCA979B0" box="[798,887,954,980]" captionStart="Fig" captionStartId="39.[191,234,1845,1871]" captionTargetBox="[195,1392,1361,1805]" captionTargetId="figure-432@39.[189,1398,1339,1807]" captionTargetPageId="39" captionText="Fig. 28.Reconstructionand interpretation of detailsof connecting ring and septal necks.A–B. Bactroceras boliviensisAubrechtová, 2015.A. Specimen FMNH-P30243, see Fig. 27D.B. Specimen FMNH-P30215, see Fig.29A.C. Eosomichelinoceras borealis sp. nov., from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen, specimen FMNH-P30305, see Fig. 33C. Black: septal neck and septum. Dark grey: connecting ring. Light grey: endosiphuncular deposits. Without scale." figureDoi="http://doi.org/10.5281/zenodo.5793508" httpUri="https://zenodo.org/record/5793508/files/figure.png" pageId="37" pageNumber="38">28A–B</figureCitation>
), contain an irregular conical continuous endosiphuncular lining, which adapically fills the entire siphuncle but thins out adorally within a length of ca 
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at conch diameters of up to 
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.
</paragraph>
<paragraph id="D75236BAFF89FF88FF6B7B56FC0F7B22" blockId="37.[188,1401,1089,1433]" lastBlockId="38.[189,1399,265,327]" lastPageId="38" lastPageNumber="39" pageId="37" pageNumber="38">
The conch apex consists of a nearly spherical protoconch with a mean diameter of 
<quantity id="10159B5FFF89FF8BFB687B56FAC27E38" box="[1214,1308,1090,1116]" metricMagnitude="-3" metricUnit="m" metricValue="1.1" pageId="37" pageNumber="38" unit="mm" value="1.1">1.1 mm</quantity>
(1 
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–3 
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quantile: 1.1–1.2; n = 15) and a mean length of 
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(1 
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–3 
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quantile: 1.0–1.1; n = 15), which is distinguished from a shaft by a shallow, often very indistinct constriction (
<figureCitation id="4FD62A3FFF89FF8BFBC87B9CFB5B7EC6" box="[1054,1157,1160,1186]" captionStart="Fig" captionStartId="22.[189,232,1536,1562]" captionTargetId="figure-11@21.[189,1398,272,2011]" captionTargetPageId="21" captionText="Fig. 12 (previous page). Apical parts of orthoconic cephalopods from the Olenidsletta Member, Floian, Ordovician, near Hinlopenstretet, Ny Friesland, Spitsbergen. A. Cyptendoceras sp. B., FMNH-P30472 from Profilbekken river basin, locality PR-phosphatic. Lateral view with siphuncle toward the left. B. Svalbardoceras sterna gen. et sp. nov, FMNH-P30169, from PO 7.5. Lateral view with siphuncle toward left. C, F–G. Eosomichelinoceras borealis sp. nov. C. Specimen FMNH-P30171, from bed PO 123.3. Lateral view with prosiphuncular side toward the right. D. Bactroceras fluvii sp. nov., FMNH-P30168, from Profilbekken river basin, locality PR-phosphatic, showing the ventral side with ventral sutural lobe. E, H, J. Bactroceras boliviensis Aubrechtová, 2015 from bed PO 131. E. Specimen FMNH-P30165, nearly dorsal view, showing the transition of the extreme apical part toward the juvenile part of the conch. F. Specimen FMNH-P30182, lateral view with siphuncle toward the right. G. Specimen FMNH-P30184, lateral view with siphuncle toward the left. H. Specimen FMNH-P30183, apical view, showing the smooth apical surface of the protoconch. I. Ethanoceras solitudines gen. et sp. nov., FMNH-P30173, from bed PO 123.3, note the fine transverse striation. J. FMNH-P30160, showing details of fine transverse ornamentation. Scale bar = 2 mm for all figures." figureDoi="http://doi.org/10.5281/zenodo.5794307" httpUri="https://zenodo.org/record/5794307/files/figure.png" pageId="37" pageNumber="38">Figs 12J</figureCitation>
, 
<figureCitation id="4FD62A3FFF89FF8BFB467B9CFB1B7EC6" box="[1168,1221,1160,1186]" captionStart="Fig" captionStartId="40.[189,232,1780,1806]" captionTargetBox="[369,1217,265,1736]" captionTargetId="figure-13@40.[369,1218,265,1743]" captionTargetPageId="40" captionText="Fig. 29. Median sections of phragmocones of Bactroceras Holm, 1898. A, C–D. Bactroceras fluvii sp. nov., from Profilbekken river basin, locality PR-phosphatic. A. Specimen FMNH-P30159, with adapical siphuncular segment, taphonomically slightly distorted.B. Bactroceras boliviensisAubrechtová, 2015, FMNH-P30176 from bed PO 131, extreme apical part. C–D. Specimen FMNH-P30177, holotype. C. Details of the protoconch. D. Apical part with transition toward juvenile growth stages; note the slightly expanded siphuncular segments. Scale bars: A = 5 mm; B–C = 1 mm; D = 2 mm." figureDoi="http://doi.org/10.5281/zenodo.5793512" httpUri="https://zenodo.org/record/5793512/files/figure.png" pageId="37" pageNumber="38">29B</figureCitation>
). The spherical initial part is smooth, without a cicatrix (
<figureCitation id="4FD62A3FFF89FF8BFD4B7BBFFCD47EA2" box="[669,778,1195,1222]" captionStart="Fig" captionStartId="22.[189,232,1536,1562]" captionTargetId="figure-11@21.[189,1398,272,2011]" captionTargetPageId="21" captionText="Fig. 12 (previous page). Apical parts of orthoconic cephalopods from the Olenidsletta Member, Floian, Ordovician, near Hinlopenstretet, Ny Friesland, Spitsbergen. A. Cyptendoceras sp. B., FMNH-P30472 from Profilbekken river basin, locality PR-phosphatic. Lateral view with siphuncle toward the left. B. Svalbardoceras sterna gen. et sp. nov, FMNH-P30169, from PO 7.5. Lateral view with siphuncle toward left. C, F–G. Eosomichelinoceras borealis sp. nov. C. Specimen FMNH-P30171, from bed PO 123.3. Lateral view with prosiphuncular side toward the right. D. Bactroceras fluvii sp. nov., FMNH-P30168, from Profilbekken river basin, locality PR-phosphatic, showing the ventral side with ventral sutural lobe. E, H, J. Bactroceras boliviensis Aubrechtová, 2015 from bed PO 131. E. Specimen FMNH-P30165, nearly dorsal view, showing the transition of the extreme apical part toward the juvenile part of the conch. F. Specimen FMNH-P30182, lateral view with siphuncle toward the right. G. Specimen FMNH-P30184, lateral view with siphuncle toward the left. H. Specimen FMNH-P30183, apical view, showing the smooth apical surface of the protoconch. I. Ethanoceras solitudines gen. et sp. nov., FMNH-P30173, from bed PO 123.3, note the fine transverse striation. J. FMNH-P30160, showing details of fine transverse ornamentation. Scale bar = 2 mm for all figures." figureDoi="http://doi.org/10.5281/zenodo.5794307" httpUri="https://zenodo.org/record/5794307/files/figure.png" pageId="37" pageNumber="38">Fig. 12H</figureCitation>
), and the following ca 
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of the initial part of the conch is nearly smooth. In some well-preserved specimens a faint, narrow, transverse ornamentation is visible, which becomes more pronounced during growth. The shaft and the following ca 
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are almost straight and have a very low angle of expansion or are tubular. At a distance of 
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from the apical tip the conch is only 
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wide in specimen FMNH-P30165. The caecum is elongated; in specimen FMNH-P30176 it is ca 
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long and 
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wide, directly marginal and reaches only through the adoral half of the initial chamber, which is 
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long. Septal crowing occurs in specimen FMNH-P30176 between the second to fourth septum with a distance between 0.4 and 
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, and the subsequent four chambers have a length of 
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(
<figureCitation id="4FD62A3FFF8AFF88FC8E7E38FC1D7B22" box="[856,963,300,326]" captionStart="Fig" captionStartId="40.[189,232,1780,1806]" captionTargetBox="[369,1217,265,1736]" captionTargetId="figure-13@40.[369,1218,265,1743]" captionTargetPageId="40" captionText="Fig. 29. Median sections of phragmocones of Bactroceras Holm, 1898. A, C–D. Bactroceras fluvii sp. nov., from Profilbekken river basin, locality PR-phosphatic. A. Specimen FMNH-P30159, with adapical siphuncular segment, taphonomically slightly distorted.B. Bactroceras boliviensisAubrechtová, 2015, FMNH-P30176 from bed PO 131, extreme apical part. C–D. Specimen FMNH-P30177, holotype. C. Details of the protoconch. D. Apical part with transition toward juvenile growth stages; note the slightly expanded siphuncular segments. Scale bars: A = 5 mm; B–C = 1 mm; D = 2 mm." figureDoi="http://doi.org/10.5281/zenodo.5793512" httpUri="https://zenodo.org/record/5793512/files/figure.png" pageId="38" pageNumber="39">Fig. 29B</figureCitation>
).
</paragraph>
</subSubSection>
<caption id="83926632FF89FF8BFF6A784EFD467DBB" ID-DOI="http://doi.org/10.5281/zenodo.5793502" ID-Zenodo-Dep="5793502" httpUri="https://zenodo.org/record/5793502/files/figure.png" pageId="37" pageNumber="38" startId="37.[188,231,1882,1908]" targetBox="[388,1203,1512,1836]" targetPageId="37">
<paragraph id="D75236BAFF89FF8BFF6A784EFD467DBB" blockId="37.[188,1398,1882,2015]" pageId="37" pageNumber="38">
<emphasis id="E599EAA8FF89FF8BFF6A784EFEC37D10" bold="true" box="[188,285,1882,1908]" pageId="37" pageNumber="38">Fig. 26.</emphasis>
Diagrams of relative siphuncular diameter and relative siphuncular distance of 
<taxonomicName id="10ED4D39FF89FF8BFB3E784FFDE87DFD" authority="Aubrechtova, 2015" authorityName="Aubrechtova" authorityYear="2015" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="37" pageNumber="38" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF89FF8BFB3E784FFEE47DFC" italics="true" pageId="37" pageNumber="38">Bactroceras boliviensis</emphasis>
<bibRefCitation id="B37C4B4BFF89FF8BFE9F786AFDE87DFD" author="Aubrechtova M." box="[329,566,1918,1945]" pageId="37" pageNumber="38" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová, 2015</bibRefCitation>
</taxonomicName>
, from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimen from 
<bibRefCitation id="B37C4B4BFF89FF8BFB9978B5FA9F7DD8" author="Aubrechtova M." box="[1103,1345,1953,1980]" pageId="37" pageNumber="38" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová (2015)</bibRefCitation>
. See Supp. file 1 for details of measurements.
</paragraph>
</caption>
<subSubSection id="9FF76531FF8AFF87FF6B7E7AFCF378C8" lastPageId="41" lastPageNumber="42" pageId="38" pageNumber="39" type="discussion">
<paragraph id="D75236BAFF8AFF88FF6B7E7AFEF17BEC" blockId="38.[189,303,366,392]" box="[189,303,366,392]" pageId="38" pageNumber="39">
<heading id="8C1A81D6FF8AFF88FF6B7E7AFEF17BEC" bold="true" box="[189,303,366,392]" fontSize="11" level="3" pageId="38" pageNumber="39" reason="3">
<emphasis id="E599EAA8FF8AFF88FF6B7E7AFEF17BEC" bold="true" box="[189,303,366,392]" pageId="38" pageNumber="39">Remarks</emphasis>
</heading>
</paragraph>
<paragraph id="D75236BAFF8AFF89FF6B7E88FBDD7B0D" blockId="38.[189,1399,412,474]" lastBlockId="39.[186,1399,265,362]" lastPageId="39" lastPageNumber="40" pageId="38" pageNumber="39">
The assignment of the specimens described above to 
<taxonomicName id="10ED4D39FF8AFF88FCF57E89FC1F7BD2" authorityName="Aubrechtova" authorityYear="2015" box="[803,961,412,439]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8AFF88FCF57E89FCEB7BD2" box="[803,821,413,438]" italics="true" pageId="38" pageNumber="39">B</emphasis>
. 
<emphasis id="E599EAA8FF8AFF88FC927E88FC1F7BD2" box="[836,961,412,438]" italics="true" pageId="38" pageNumber="39">boliviensis</emphasis>
</taxonomicName>
is justified herein by the combination of the distinctively pronounced transverse ornamentation, a relatively wide siphuncle, and a relatively large adult size. The relative siphuncular diameter of the Olenidsletta Member specimens is on average slightly wider than that of the 
<typeStatus id="08568818FF8BFF89FDD87E38FDAB7B22" box="[526,629,300,326]" pageId="39" pageNumber="40" type="holotype">holotype</typeStatus>
and 
<typeStatus id="08568818FF8BFF89FD7F7E39FCDA7B23" box="[681,772,301,327]" pageId="39" pageNumber="40" type="syntype">syntype</typeStatus>
of 
<taxonomicName id="10ED4D39FF8BFF89FCF57E39FC1F7B22" authorityName="Aubrechtova" authorityYear="2015" box="[803,961,300,327]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8BFF89FCF57E39FCEB7B22" box="[803,821,301,326]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FC927E38FC1F7B22" box="[836,961,300,326]" italics="true" pageId="39" pageNumber="40">boliviensis</emphasis>
</taxonomicName>
. However, the range of measurements of the 
<specimenCount id="C1EBFD33FF8BFF89FED37E44FEA97B0E" box="[261,375,336,362]" pageId="39" pageNumber="40" type="generic">two types</specimenCount>
is well within the range of our specimens (see 
<figureCitation id="4FD62A3FFF8BFF89FC497E5BFC287B0D" box="[927,1014,335,361]" captionStart="Fig" captionStartId="35.[189,232,1880,1906]" captionTargetBox="[204,1395,1485,1808]" captionTargetId="figure-405@35.[189,1398,1475,1815]" captionTargetPageId="35" captionText="Fig. 24. Diagrams of spacing of ornamentation, angle of expansion, and relative chamber length of Bactroceras boliviensis Aubrechtová, 2015 from the Olenidsletta Member (Olen. Mbr), Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Data of type specimens from Aubrechtová (2015). See Supp. file 1 for details of measurements." figureDoi="http://doi.org/10.5281/zenodo.5793498" httpUri="https://zenodo.org/record/5793498/files/figure.png" pageId="39" pageNumber="40">Fig. 24</figureCitation>
).
</paragraph>
<caption id="83926632FF8AFF88FF687828FBF37D80" ID-DOI="http://doi.org/10.5281/zenodo.5793506" ID-Zenodo-Dep="5793506" httpUri="https://zenodo.org/record/5793506/files/figure.png" pageId="38" pageNumber="39" startId="38.[190,233,1852,1878]" targetBox="[196,1394,551,1812]" targetPageId="38">
<paragraph id="D75236BAFF8AFF88FF687828FBF37D80" blockId="38.[189,1399,1852,2020]" pageId="38" pageNumber="39">
<emphasis id="E599EAA8FF8AFF88FF687828FEFE7D32" bold="true" box="[190,288,1852,1878]" pageId="38" pageNumber="39">Fig. 27.</emphasis>
Median sections of phragmocones of 
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<emphasis id="E599EAA8FF8AFF88FD207829FBD37D32" box="[758,1037,1852,1878]" italics="true" pageId="38" pageNumber="39">Bactroceras boliviensis</emphasis>
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</taxonomicName>
, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. Note conical endisiphuncular lining in A–D. 
<emphasis id="E599EAA8FF8AFF88FD457896FD767DF8" bold="true" box="[659,680,1922,1948]" pageId="38" pageNumber="39">A</emphasis>
. Specimen FMNH-P30215, from bed PO 131. 
<emphasis id="E599EAA8FF8AFF88FB377897FB2D7DF9" bold="true" box="[1249,1267,1923,1949]" pageId="38" pageNumber="39">B</emphasis>
. Specimen FMNH-P30259, from bed PO 7.5. 
<emphasis id="E599EAA8FF8AFF88FDBE78B2FD7F7DA4" bold="true" box="[616,673,1958,1984]" pageId="38" pageNumber="39">C–D</emphasis>
. Specimen FMNH-P30243, from bed PO 7.5. 
<emphasis id="E599EAA8FF8AFF88FB0B78B2FB2F7DA4" bold="true" box="[1245,1265,1958,1984]" pageId="38" pageNumber="39">E</emphasis>
. Specimen FMNH-P30383, from bed PO 131. Scale bars: A–C, E = 5 mm; D = 1 mm.
</paragraph>
</caption>
<paragraph id="D75236BAFF8BFF89FF6B7E85FD8E7968" blockId="39.[188,1400,401,780]" pageId="39" pageNumber="40">
Another species of 
<taxonomicName id="10ED4D39FF8BFF89FE737E86FDED7BCF" authorityName="Holm" authorityYear="1898" box="[421,563,402,427]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="E599EAA8FF8BFF89FE737E86FDED7BCF" box="[421,563,402,427]" italics="true" pageId="39" pageNumber="40">Bactroceras</emphasis>
</taxonomicName>
with a similarly wide siphuncle (rSD = ¹/6) is 
<taxonomicName id="10ED4D39FF8BFF89FB8A7E86FAA97BCF" authority="Flower, 1968" authorityName="Flower" authorityYear="1968" box="[1116,1399,401,427]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="wilsoni">
<emphasis id="E599EAA8FF8BFF89FB8A7E86FBB37BCF" box="[1116,1133,402,427]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FBAB7E85FB0C7BCF" box="[1149,1234,401,427]" italics="true" pageId="39" pageNumber="40">wilsoni</emphasis>
<bibRefCitation id="B37C4B4BFF8BFF89FB0C7E85FAA97BCF" author="Flower R. H." box="[1242,1399,401,427]" pageId="39" pageNumber="40" pagination="1 - 120" refId="ref46516" refString="Flower R. H. 1968. Part I. The first great expansion of the actinoceroids. Part II. Some additional Whiterock cephalopods. New Mexico Bureau of Mines and Mineral Resources, Memoir 19: 1 - 120." type="journal article" year="1968">Flower, 1968</bibRefCitation>
</taxonomicName>
from the Antelope Valley Limestone, 
<collectingRegion id="1529F858FF8BFF89FDA37EA0FD0C7BAA" box="[629,722,436,462]" country="United States of America" name="Nevada" pageId="39" pageNumber="40">Nevada</collectingRegion>
, 
<collectingCountry id="AFFA762AFF8BFF89FD0B7EA0FCC57BAA" box="[733,795,436,462]" name="United States of America" pageId="39" pageNumber="40">USA</collectingCountry>
, which differs, however, in lacking the distinctively striated ornamentation. The 
<typeStatus id="08568818FF8BFF89FDD17ECCFD9B7B96" box="[519,581,472,498]" pageId="39" pageNumber="40">types</typeStatus>
of 
<taxonomicName id="10ED4D39FF8BFF89FDBA7ECCFBF37B95" authority="(Rudiger, 1889)" baseAuthorityName="Rudiger" baseAuthorityYear="1891" box="[620,1069,471,498]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="angustisiphonatum">
<emphasis id="E599EAA8FF8BFF89FDBA7ECCFDA07B95" box="[620,638,472,497]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FD5B7EC3FCB27B95" box="[653,876,471,497]" italics="true" pageId="39" pageNumber="40">angustisiphonatum</emphasis>
(
<bibRefCitation id="B37C4B4BFF8BFF89FCAD7EC3FBFB7B95" author="Rudiger H." box="[891,1061,471,497]" pageId="39" pageNumber="40" refId="ref49685" refString="Rudiger H. 1889. Ueber die Silur-Cephalopoden aus den Mecklenburgischen Diluvialgeschieben. Rathsbuchdruckerei von C. Michaal &amp; A. Schuster, Gustrow, Germany. https: // doi. org / 10.5962 / bhl. title. 14078" type="book" year="1889">Rüdiger, 1889</bibRefCitation>
)
</taxonomicName>
differ from the 
<taxonomicName id="10ED4D39FF8BFF89FB3E7ECCFAA87B95" authorityName="Holm" authorityYear="1898" box="[1256,1398,472,497]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="E599EAA8FF8BFF89FB3E7ECCFAA87B95" box="[1256,1398,472,497]" italics="true" pageId="39" pageNumber="40">Bactroceras</emphasis>
</taxonomicName>
specimens of the Olenidsletta Member in having a very narrow siphuncle with an rSD of ca ¹/12 (
<bibRefCitation id="B37C4B4BFF8BFF89FAE47EEEFEC2785C" author="Holm G." pageId="39" pageNumber="40" pagination="354 - 360" refId="ref47786" refString="Holm G. 1898. Palaeontologiska notiser. Om ett par Bactrites - liknande untersiluriska orthocer-former. Geologiska Foreningen i Stockholm Forhandlingar 20: 354 - 360. https: // doi. org / 10.1080 / 11035899809447943" type="journal article" year="1898">Holm 1898: 9</bibRefCitation>
) to ¹/11 (
<bibRefCitation id="B37C4B4BFF8BFF89FE427D0AFDAD785C" author="Rudiger H." box="[404,627,542,568]" pageId="39" pageNumber="40" refId="ref49685" refString="Rudiger H. 1889. Ueber die Silur-Cephalopoden aus den Mecklenburgischen Diluvialgeschieben. Rathsbuchdruckerei von C. Michaal &amp; A. Schuster, Gustrow, Germany. https: // doi. org / 10.5962 / bhl. title. 14078" type="book" year="1889">Rüdiger 1889: 37</bibRefCitation>
). Additionally, the ornamentation of 
<taxonomicName id="10ED4D39FF8BFF89FB957D0AFA97785C" baseAuthorityName="Rudiger" baseAuthorityYear="1891" box="[1091,1353,542,568]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="angustisiphonatum">
<emphasis id="E599EAA8FF8BFF89FB957D0AFB8B7853" box="[1091,1109,542,567]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FBBC7D0AFA97785C" box="[1130,1353,542,568]" italics="true" pageId="39" pageNumber="40">angustisiphonatum</emphasis>
</taxonomicName>
, as originally described by 
<bibRefCitation id="B37C4B4BFF8BFF89FE197D55FD6E783F" author="Rudiger H." box="[463,688,577,603]" pageId="39" pageNumber="40" refId="ref49685" refString="Rudiger H. 1889. Ueber die Silur-Cephalopoden aus den Mecklenburgischen Diluvialgeschieben. Rathsbuchdruckerei von C. Michaal &amp; A. Schuster, Gustrow, Germany. https: // doi. org / 10.5962 / bhl. title. 14078" type="book" year="1889">Rüdiger (1889: 37)</bibRefCitation>
, is weak; 
<bibRefCitation id="B37C4B4BFF8BFF89FCF47D55FC0A783F" author="Rudiger H." box="[802,980,577,603]" pageId="39" pageNumber="40" refId="ref49685" refString="Rudiger H. 1889. Ueber die Silur-Cephalopoden aus den Mecklenburgischen Diluvialgeschieben. Rathsbuchdruckerei von C. Michaal &amp; A. Schuster, Gustrow, Germany. https: // doi. org / 10.5962 / bhl. title. 14078" type="book" year="1889">Rüdiger (1889)</bibRefCitation>
referred to it as “Anwachsstreifen”, i.e., growth lines (this is in contrast to his use of the term “Ringlinien”, i.e., transverse striae, e.g., 
<bibRefCitation id="B37C4B4BFF8BFF89FF6B7D93FE5178C5" author="Rudiger H." box="[189,399,647,673]" pageId="39" pageNumber="40" refId="ref49685" refString="Rudiger H. 1889. Ueber die Silur-Cephalopoden aus den Mecklenburgischen Diluvialgeschieben. Rathsbuchdruckerei von C. Michaal &amp; A. Schuster, Gustrow, Germany. https: // doi. org / 10.5962 / bhl. title. 14078" type="book" year="1889">Rüdiger 1889: 38</bibRefCitation>
). The relatively weak ornamentation, with growth lines only, of the original material of 
<taxonomicName id="10ED4D39FF8BFF89FF347DBFFE3978A0" baseAuthorityName="Rudiger" baseAuthorityYear="1891" box="[226,487,682,709]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="angustisiphonatum">
<emphasis id="E599EAA8FF8BFF89FF347DBFFF2A78A0" box="[226,244,683,708]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FEDE7DBEFE3978A0" box="[264,487,682,708]" italics="true" pageId="39" pageNumber="40">angustisiphonatum</emphasis>
</taxonomicName>
is also explicitly mentioned in 
<bibRefCitation id="B37C4B4BFF8BFF89FCAF7DBEFBE378A1" author="Holm G." box="[889,1085,682,709]" pageId="39" pageNumber="40" pagination="354 - 360" refId="ref47786" refString="Holm G. 1898. Palaeontologiska notiser. Om ett par Bactrites - liknande untersiluriska orthocer-former. Geologiska Foreningen i Stockholm Forhandlingar 20: 354 - 360. https: // doi. org / 10.1080 / 11035899809447943" type="journal article" year="1898">Holm (1898: 9)</bibRefCitation>
. 
<taxonomicName id="10ED4D39FF8BFF89FB997DBFFE5B788C" authority="(Barrande, 1867)" baseAuthorityName="Barrande" baseAuthorityYear="1867" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="sandbergeri">
<emphasis id="E599EAA8FF8BFF89FB997DBFFAA978A0" box="[1103,1399,682,708]" italics="true" pageId="39" pageNumber="40">Bactroceras sandbergeri</emphasis>
(Barrande, 1867)
</taxonomicName>
differs also in having a siphuncle with a diameter of &lt;0.1 of the corresponding conch cross section (
<bibRefCitation id="B37C4B4BFF8BFF89FEB57DE5FD9A7968" author="Aubrechtova M." box="[355,580,753,780]" pageId="39" pageNumber="40" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová 2015</bibRefCitation>
).
</paragraph>
<paragraph id="D75236BAFF8BFF87FF6B7C27FABB7BE9" blockId="39.[187,1399,818,1267]" lastBlockId="41.[188,1400,265,397]" lastPageId="41" lastPageNumber="42" pageId="39" pageNumber="40">
<bibRefCitation id="B37C4B4BFF8BFF89FF6B7C27FE827929" author="Evans D. H." box="[189,348,818,845]" pageId="39" pageNumber="40" pagination="1 - 81" refId="ref46068" refString="Evans D. H. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 628: 1 - 81." type="journal article" year="2005">Evans (2005)</bibRefCitation>
described an assemblage of ca 
<specimenCount id="C1EBFD33FF8BFF89FD0A7C26FCA37928" box="[732,893,818,844]" pageId="39" pageNumber="40" type="generic">40 specimens</specimenCount>
from the Olenidssletta Member, collected by R.A. Fortey and D.L. Bruton, under “ 
<taxonomicName id="10ED4D39FF8BFF89FD4F7C42FB827914" authority="(Rudiger, 1891)" baseAuthorityName="Rudiger" baseAuthorityYear="1891" box="[665,1116,853,880]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="angustisiphonatum">
<emphasis id="E599EAA8FF8BFF89FD4F7C42FD75790B" box="[665,683,854,879]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FD6C7C41FC47790B" box="[698,921,853,879]" italics="true" pageId="39" pageNumber="40">angustisiphonatum</emphasis>
(Rüdiger, 1891)
</taxonomicName>
” (sic!). The assemblage came from “the top of division V 2 ” (
<bibRefCitation id="B37C4B4BFF8BFF89FD577C6DFC9A79F7" author="Evans D. H." box="[641,836,888,915]" pageId="39" pageNumber="40" pagination="1 - 81" refId="ref46068" refString="Evans D. H. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 628: 1 - 81." type="journal article" year="2005">Evans 2005: 28</bibRefCitation>
), with high probability from exactly the same horizon as most of the specimens assigned to 
<taxonomicName id="10ED4D39FF8BFF89FD187C89FCB579D2" authorityName="Aubrechtova" authorityYear="2015" box="[718,875,924,950]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8BFF89FD187C89FD3E79D2" box="[718,736,925,950]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FD387C88FCB579D2" box="[750,875,924,950]" italics="true" pageId="39" pageNumber="40">boliviensis</emphasis>
</taxonomicName>
herein. 
<taxonomicName id="10ED4D39FF8BFF89FC1F7C89FB0579D2" authorityName="Aubrechtova" authorityYear="2015" box="[969,1243,924,950]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8BFF89FC1F7C89FB0579D2" box="[969,1243,924,950]" italics="true" pageId="39" pageNumber="40">Bactroceras boliviensis</emphasis>
</taxonomicName>
is distinctive within the orthocones of the Olenidssletta Member and occurs in great numbers at 
<quantity id="10159B5FFF8BFF89FB7D7CABFB2679BE" box="[1195,1272,959,986]" metricMagnitude="2" metricUnit="m" metricValue="1.28" pageId="39" pageNumber="40" unit="m" value="128.0">128 m</quantity>
above the base of the member at Profilstranda. The specimens from the Olenidssletta Member described by 
<bibRefCitation id="B37C4B4BFF8BFF89FAF97CF7FED57E44" author="Evans D. H." pageId="39" pageNumber="40" pagination="1 - 81" refId="ref46068" refString="Evans D. H. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 628: 1 - 81." type="journal article" year="2005">Evans (2005)</bibRefCitation>
are therefore with high probability in large part conspecific with the specimens described herein under 
<taxonomicName id="10ED4D39FF8BFF89FED17B3DFE7B7E27" authorityName="Aubrechtova" authorityYear="2015" box="[263,421,1065,1091]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8BFF89FED17B3DFEC77E26" box="[263,281,1065,1090]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FEFE7B3DFE7B7E27" box="[296,421,1065,1091]" italics="true" pageId="39" pageNumber="40">boliviensis</emphasis>
</taxonomicName>
. Our measurements add to the knowledge of the variability of this assemblage, and specifically the dimensions and characters of the apical parts are almost identical (compare 
<bibRefCitation id="B37C4B4BFF8BFF89FB337B58FAAD7E03" author="Evans D. H." box="[1253,1395,1100,1127]" pageId="39" pageNumber="40" pagination="1 - 81" refId="ref46068" refString="Evans D. H. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 628: 1 - 81." type="journal article" year="2005">Evans 2005</bibRefCitation>
: text-fig. 8e). However, 
<taxonomicName id="10ED4D39FF8BFF89FE007B64FDA97EED" authorityName="Aubrechtova" authorityYear="2015" box="[470,631,1135,1162]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8BFF89FE007B64FE367EED" box="[470,488,1136,1161]" italics="true" pageId="39" pageNumber="40">B</emphasis>
. 
<emphasis id="E599EAA8FF8BFF89FE2C7B7BFDA97EED" box="[506,631,1135,1161]" italics="true" pageId="39" pageNumber="40">boliviensis</emphasis>
</taxonomicName>
co-occurs with 
<taxonomicName id="10ED4D39FF8BFF89FCEB7B7BFB847EED" authority="Kröger &amp; Pohle, 2021" authorityName="Kröger &amp; Pohle" authorityYear="2021" box="[829,1114,1135,1161]" class="Cephalopoda" family="Rioceratidae" genus="Ethanoceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Tetrabranchia" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="solitudines" status="gen. et sp. nov.">
<emphasis id="E599EAA8FF8BFF89FCEB7B7BFB847EED" box="[829,1114,1135,1161]" italics="true" pageId="39" pageNumber="40">Ethanoceras solitudines</emphasis>
</taxonomicName>
<taxonomicNameLabel id="FEAA57D3FF8BFF89FBB27B64FAFE7EEE" box="[1124,1312,1136,1162]" pageId="39" pageNumber="40" rank="species">gen. et sp. nov.</taxonomicNameLabel>
, which differs in having a less pronounced ornamentation and a non-marginal, eccentrically positioned siphuncle throughout its entire growth. This makes the distinction between 
<taxonomicName id="10ED4D39FF8BFF89FC617BA2FB9B7EAB" authorityName="Holm" authorityYear="1898" box="[951,1093,1206,1231]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="E599EAA8FF8BFF89FC617BA2FB9B7EAB" box="[951,1093,1206,1231]" italics="true" pageId="39" pageNumber="40">Bactroceras</emphasis>
</taxonomicName>
and 
<taxonomicName id="10ED4D39FF8BFF89FBA87BA1FACC7EAB" authorityName="Kröger &amp; Pohle" authorityYear="2021" box="[1150,1298,1205,1231]" class="Cephalopoda" family="Rioceratidae" genus="Ethanoceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Tetrabranchia" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="E599EAA8FF8BFF89FBA87BA1FACC7EAB" box="[1150,1298,1205,1231]" italics="true" pageId="39" pageNumber="40">Ethanoceras</emphasis>
</taxonomicName>
difficult or impossible in specimens with diameters &lt;
<quantity id="10159B5FFF8BFF89FD007BCCFCC27E97" box="[726,796,1240,1267]" metricMagnitude="-3" metricUnit="m" metricValue="6.0" pageId="39" pageNumber="40" unit="mm" value="6.0">6 mm</quantity>
and without well preserved outer shell or extreme apical parts. Therefore, we measured only specimens with a well-preserved shell surface. Our results differ slightly from the measurements of 
<bibRefCitation id="B37C4B4BFF85FF87FD4C7E39FCEF7B23" author="Evans D. H." box="[666,817,300,327]" pageId="41" pageNumber="42" pagination="1 - 81" refId="ref46068" refString="Evans D. H. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 628: 1 - 81." type="journal article" year="2005">Evans (2005</bibRefCitation>
: text-fig. 8) in having a strictly marginal siphuncle position in 
<taxonomicName id="10ED4D39FF85FF87FEEB7E44FE047B0D" authorityName="Aubrechtova" authorityYear="2015" box="[317,474,335,362]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF85FF87FEEB7E44FE917B0D" box="[317,335,336,361]" italics="true" pageId="41" pageNumber="42">B</emphasis>
. 
<emphasis id="E599EAA8FF85FF87FE8B7E5BFE047B0D" box="[349,474,335,361]" italics="true" pageId="41" pageNumber="42">boliviensis</emphasis>
</taxonomicName>
in specimens with diameters&gt;ca 
<quantity id="10159B5FFF85FF87FCB57E5BFC187B0E" box="[867,966,335,362]" metricMagnitude="-3" metricUnit="m" metricValue="6.5" metricValueMax="7.0" metricValueMin="6.0" pageId="41" pageNumber="42" unit="mm" value="6.5" valueMax="7.0" valueMin="6.0">6–7 mm</quantity>
. This difference is potentially a result of unrecognized specimens of 
<taxonomicName id="10ED4D39FF85FF87FDF57E66FCE07BE8" authority="Kröger &amp; Pohle, 2021" authorityName="Kröger &amp; Pohle" authorityYear="2021" box="[547,830,370,396]" class="Cephalopoda" family="Rioceratidae" genus="Ethanoceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Tetrabranchia" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="solitudines" status="gen. et sp. nov.">
<emphasis id="E599EAA8FF85FF87FDF57E66FCE07BE8" box="[547,830,370,396]" italics="true" pageId="41" pageNumber="42">Ethanoceras solitudines</emphasis>
</taxonomicName>
<taxonomicNameLabel id="FEAA57D3FF85FF87FC937E67FC287BE9" box="[837,1014,371,397]" pageId="41" pageNumber="42" rank="species">gen. et sp. nov.</taxonomicNameLabel>
in the sample of 
<bibRefCitation id="B37C4B4BFF85FF87FB167E67FABF7BE9" author="Evans D. H." box="[1216,1377,370,397]" pageId="41" pageNumber="42" pagination="1 - 81" refId="ref46068" refString="Evans D. H. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 628: 1 - 81." type="journal article" year="2005">Evans (2005)</bibRefCitation>
.
</paragraph>
<caption id="83926632FF8BFF89FF697821FA997DB8" ID-DOI="http://doi.org/10.5281/zenodo.5793508" ID-Zenodo-Dep="5793508" httpUri="https://zenodo.org/record/5793508/files/figure.png" pageId="39" pageNumber="40" startId="39.[191,234,1845,1871]" targetBox="[195,1392,1361,1805]" targetPageId="39">
<paragraph id="D75236BAFF8BFF89FF697821FA997DB8" blockId="39.[186,1398,1845,2012]" pageId="39" pageNumber="40">
<emphasis id="E599EAA8FF8BFF89FF697821FEC77D2B" bold="true" box="[191,281,1845,1871]" pageId="39" pageNumber="40">Fig. 28.</emphasis>
Reconstruction and interpretation of details of connecting ring and septal necks. 
<emphasis id="E599EAA8FF8BFF89FB747821FB047D2B" bold="true" box="[1186,1242,1845,1871]" pageId="39" pageNumber="40">A–B</emphasis>
. 
<taxonomicName id="10ED4D39FF8BFF89FB3E7822FDC17D17" authority="Aubrechtova, 2015" authorityName="Aubrechtova" authorityYear="2015" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF8BFF89FB3E7822FEE47D16" italics="true" pageId="39" pageNumber="40">Bactroceras boliviensis</emphasis>
<bibRefCitation id="B37C4B4BFF8BFF89FEEB784CFDC17D17" author="Aubrechtova M." box="[317,543,1880,1907]" pageId="39" pageNumber="40" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová, 2015</bibRefCitation>
</taxonomicName>
. 
<emphasis id="E599EAA8FF8BFF89FDF5784CFDE67D16" bold="true" box="[547,568,1880,1906]" pageId="39" pageNumber="40">A</emphasis>
. Specimen FMNH-P30243, see Fig. 27D. 
<emphasis id="E599EAA8FF8BFF89FBCB784CFBEF7D16" bold="true" box="[1053,1073,1880,1906]" pageId="39" pageNumber="40">B</emphasis>
. Specimen FMNH-P30215, see Fig.29A. 
<emphasis id="E599EAA8FF8BFF89FE82786FFEB77DF1" bold="true" box="[340,361,1915,1941]" pageId="39" pageNumber="40">C</emphasis>
. 
<taxonomicName id="10ED4D39FF8BFF89FEAE786FFD177DF1" authority="Kröger &amp; Pohle, 2021" authorityName="Kröger &amp; Pohle" authorityYear="2021" box="[376,713,1915,1941]" class="Cephalopoda" family="Baltoceratidae" genus="Eosomichelinoceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="borealis" status="sp. nov.">
<emphasis id="E599EAA8FF8BFF89FEAE786FFD177DF1" box="[376,713,1915,1941]" italics="true" pageId="39" pageNumber="40">Eosomichelinoceras borealis</emphasis>
</taxonomicName>
<taxonomicNameLabel id="FEAA57D3FF8BFF89FD1B7868FCF97DF2" box="[717,807,1916,1942]" pageId="39" pageNumber="40" rank="species">sp. nov.</taxonomicNameLabel>
, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen, specimen FMNH-P30305, see Fig. 33C. Black: septal neck and septum. Dark grey: connecting ring. Light grey: endosiphuncular deposits. Without scale.
</paragraph>
</caption>
<caption id="83926632FF84FF86FF6B79E0FB0A7DDB" ID-DOI="http://doi.org/10.5281/zenodo.5793512" ID-Zenodo-Dep="5793512" httpUri="https://zenodo.org/record/5793512/files/figure.png" pageId="40" pageNumber="41" startId="40.[189,232,1780,1806]" targetBox="[369,1217,265,1736]" targetPageId="40">
<paragraph id="D75236BAFF84FF86FF6B79E0FB0A7DDB" blockId="40.[184,1399,1780,1983]" pageId="40" pageNumber="41">
<emphasis id="E599EAA8FF84FF86FF6B79E0FEC07D6A" bold="true" box="[189,286,1780,1806]" pageId="40" pageNumber="41">Fig. 29.</emphasis>
Median sections of phragmocones of 
<taxonomicName id="10ED4D39FF84FF86FD2279E1FBFF7D6B" authority="Holm, 1898" authorityName="Holm" authorityYear="1898" box="[756,1057,1780,1807]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="E599EAA8FF84FF86FD2279E1FC5C7D6A" box="[756,898,1781,1806]" italics="true" pageId="40" pageNumber="41">Bactroceras</emphasis>
<bibRefCitation id="B37C4B4BFF84FF86FC5B79E0FBFF7D6B" author="Holm G." box="[909,1057,1780,1807]" pageId="40" pageNumber="41" pagination="354 - 360" refId="ref47786" refString="Holm G. 1898. Palaeontologiska notiser. Om ett par Bactrites - liknande untersiluriska orthocer-former. Geologiska Foreningen i Stockholm Forhandlingar 20: 354 - 360. https: // doi. org / 10.1080 / 11035899809447943" type="journal article" year="1898">Holm, 1898</bibRefCitation>
</taxonomicName>
. 
<emphasis id="E599EAA8FF84FF86FBE679E0FB4E7D6A" bold="true" box="[1072,1168,1780,1806]" pageId="40" pageNumber="41">A, C–D</emphasis>
. 
<taxonomicName id="10ED4D39FF84FF86FB7479E1FAA97D6A" authority="Kröger &amp; Pohle, 2021" authorityName="Kröger &amp; Pohle" authorityYear="2021" box="[1186,1399,1780,1806]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="fluvii" status="sp. nov.">
<emphasis id="E599EAA8FF84FF86FB7479E1FAA97D6A" box="[1186,1399,1780,1806]" italics="true" pageId="40" pageNumber="41">Bactroceras fluvii</emphasis>
</taxonomicName>
<taxonomicNameLabel id="FEAA57D3FF84FF86FF6B780CFEC17D56" box="[189,287,1816,1842]" pageId="40" pageNumber="41" rank="species">sp. nov.</taxonomicNameLabel>
, from Profilbekken river basin, locality PR-phosphatic. 
<emphasis id="E599EAA8FF84FF86FC197803FC3A7D55" bold="true" box="[975,996,1815,1841]" pageId="40" pageNumber="41">A</emphasis>
. Specimen FMNH-P30159, with adapical siphuncular segment, taphonomically slightly distorted. 
<emphasis id="E599EAA8FF84FF86FC75782FFC697D31" bold="true" box="[931,951,1851,1877]" pageId="40" pageNumber="41">B</emphasis>
. 
<taxonomicName id="10ED4D39FF84FF86FC137828FF287D1D" authority="Aubrechtova, 2015" authorityName="Aubrechtova" authorityYear="2015" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF84FF86FC137828FB0B7D31" box="[965,1237,1851,1877]" italics="true" pageId="40" pageNumber="41">Bactroceras boliviensis</emphasis>
<bibRefCitation id="B37C4B4BFF84FF86FB0E782FFF287D1D" author="Aubrechtova M." pageId="40" pageNumber="41" pagination="193 - 211" refId="ref45191" refString="Aubrechtova M. 2015. A revision of the Ordovician cephalopod Bactrites sandbergeri Barrande: systematic position and palaeobiogeography of Bactroceras. Geobios 48: 193 - 211. https: // doi. org / 10.1016 / j. geobios. 2015.03.002" type="journal article" year="2015">Aubrechtová, 2015</bibRefCitation>
</taxonomicName>
, FMNH-P30176 from bed PO 131, extreme apical part. 
<emphasis id="E599EAA8FF84FF86FC54784AFC647D1C" bold="true" box="[898,954,1886,1912]" pageId="40" pageNumber="41">C–D</emphasis>
. Specimen FMNH-P30177, holotype. 
<emphasis id="E599EAA8FF84FF86FF6A7895FF0F7DFF" bold="true" box="[188,209,1921,1947]" pageId="40" pageNumber="41">C</emphasis>
. Details of the protoconch. 
<emphasis id="E599EAA8FF84FF86FDFF7895FDE07DFF" bold="true" box="[553,574,1921,1947]" pageId="40" pageNumber="41">D</emphasis>
. Apical part with transition toward juvenile growth stages; note the slightly expanded siphuncular segments. Scale bars: A = 5 mm; B–C = 1 mm; D = 2 mm.
</paragraph>
</caption>
<paragraph id="D75236BAFF85FF87FF6B7EA0FDA37BAA" blockId="41.[189,637,436,462]" box="[189,637,436,462]" pageId="41" pageNumber="42">
<heading id="8C1A81D6FF85FF87FF6B7EA0FDA37BAA" bold="true" box="[189,637,436,462]" fontSize="11" level="3" pageId="41" pageNumber="42" reason="3">
<emphasis id="E599EAA8FF85FF87FF6B7EA0FDA37BAA" bold="true" box="[189,637,436,462]" pageId="41" pageNumber="42">Stratigraphic and geographic range</emphasis>
</heading>
</paragraph>
<paragraph id="D75236BAFF85FF87FF6B7EF6FCF378C8" blockId="41.[188,1399,482,684]" pageId="41" pageNumber="42">
The 
<typeStatus id="08568818FF85FF87FF227EF7FEEC7B99" box="[244,306,483,509]" pageId="41" pageNumber="42">types</typeStatus>
and previously only known specimens of 
<taxonomicName id="10ED4D39FF85FF87FCE57EF7FC0F7B98" authorityName="Aubrechtova" authorityYear="2015" box="[819,977,482,509]" class="Cephalopoda" family="Baltoceratidae" genus="Bactroceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Orthocerida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="boliviensis">
<emphasis id="E599EAA8FF85FF87FCE57EF7FC9D7B98" box="[819,835,483,508]" italics="true" pageId="41" pageNumber="42">B</emphasis>
. 
<emphasis id="E599EAA8FF85FF87FC827EF6FC0F7B98" box="[852,977,482,508]" italics="true" pageId="41" pageNumber="42">boliviensis</emphasis>
</taxonomicName>
are from the Pircancha Formation, 
<collectingCountry id="AFFA762AFF85FF87FF697D12FEC67844" box="[191,280,518,544]" name="Bolivia" pageId="41" pageNumber="42">Bolivia</collectingCountry>
, 
<taxonomicName id="10ED4D39FF85FF87FEFF7D12FDF37844" box="[297,557,518,544]" class="Graptolithina" family="Didymograptidae" genus="Baltograptus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Graptoloidea" pageId="41" pageNumber="42" phylum="Hemichordata" rank="species" species="minutus">
<emphasis id="E599EAA8FF85FF87FEFF7D12FDF37844" box="[297,557,518,544]" italics="true" pageId="41" pageNumber="42">Baltograptus minutus</emphasis>
</taxonomicName>
graptolite zone, which is time equivalent to the lower part of the 
<taxonomicName id="10ED4D39FF85FF87FF6B7D3DFE177827" baseAuthorityName="Hall" baseAuthorityYear="1865" box="[189,457,553,579]" class="Graptolithina" family="Dichograptidae" genus="Didymograptus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Graptoloidea" pageId="41" pageNumber="42" phylum="Hemichordata" rank="species" species="bifidus">
<emphasis id="E599EAA8FF85FF87FF6B7D3DFE177827" box="[189,457,553,579]" italics="true" pageId="41" pageNumber="42">Didymograptus bifidus</emphasis>
</taxonomicName>
graptolite zone (see 
<bibRefCitation id="B37C4B4BFF85FF87FD167D3DFB9D7820" author="Gutierrez-Marco J. C. &amp; Martin E. L. O." box="[704,1091,553,580]" pageId="41" pageNumber="42" pagination="35 - 49" refId="ref47400" refString="Gutierrez-Marco J. C. &amp; Martin E. L. O. 2016. Biostratigraphy and palaeoecology of Lower Ordovician graptolites from the Fezouata Shale (Moroccan Anti-Atlas). Palaeogeography, Palaeoclimatology, Palaeoecology 460: 35 - 49. https: // doi. org / 10.1016 / j. palaeo. 2016.07.026" type="journal article" year="2016">Gutiérrez-Marco &amp; Martin 2016</bibRefCitation>
). The 
<taxonomicName id="10ED4D39FF85FF87FB5A7D3EFB207827" baseAuthorityName="Hall" baseAuthorityYear="1865" box="[1164,1278,553,579]" class="Graptolithina" family="Dichograptidae" genus="Didymograptus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Graptoloidea" pageId="41" pageNumber="42" phylum="Hemichordata" rank="species" species="bifidus">
<emphasis id="E599EAA8FF85FF87FB5A7D3EFB207827" box="[1164,1278,553,579]" italics="true" pageId="41" pageNumber="42">D. bifidus</emphasis>
</taxonomicName>
graptolite zone reaches into the upper part of the V 
<subScript id="4B6934FFFF85FF87FD437D4BFD407809" attach="left" box="[661,670,607,621]" fontSize="6" pageId="41" pageNumber="42">1</subScript>
division of the Olenidsletta Member (
<bibRefCitation id="B37C4B4BFF85FF87FB8D7D58FAB47802" author="Cooper R. A. &amp; Fortey R. A." box="[1115,1386,588,615]" pageId="41" pageNumber="42" pagination="157 - 302" refId="ref45692" refString="Cooper R. A. &amp; Fortey R. A. 1982. The Ordovician graptolites of Spitsbergen. Bulletin of the British Museum (Natural History), Geology 36: 157 - 302. Available from https: // www. biodiversitylibrary. org / page / 2364287 [accessed 25 Oct. 2021]." type="journal article" year="1982">Cooper &amp; Fortey 1982</bibRefCitation>
). The specimens described herein are from V 
<subScript id="4B6934FFFF85FF87FD1E7D96FD0F78F4" attach="right" box="[712,721,642,656]" fontSize="6" pageId="41" pageNumber="42">1</subScript>
–V 
<subScript id="4B6934FFFF85FF87FD237D96FD2078F4" attach="left" box="[757,766,642,656]" fontSize="6" pageId="41" pageNumber="42">2</subScript>
trilobite zones; hence the species is known from the Blackhillsian, late Floian of 
<collectingCountry id="AFFA762AFF85FF87FDDA7D86FDBC78C8" box="[524,610,658,684]" name="Bolivia" pageId="41" pageNumber="42">Bolivia</collectingCountry>
and Spitsbergen.
</paragraph>
</subSubSection>
</treatment>
</document>