<documentid="46D269968852591FC51DDD8FCC58ECE4"ID-DOI="10.5070/P940454153"ID-ISSN="0031-0298"ID-Zenodo-Dep="10913559"ID-ZooBank="58312615-0833-432E-BF5D-3DFFBF361AAA"IM.bibliography_approvedBy="diego"IM.illustrations_approvedBy="diego"IM.materialsCitations_approvedBy="diego"IM.metadata_approvedBy="felipe"IM.tables_requiresApprovalFor="existingObjects"IM.taxonomicNames_approvedBy="diego"IM.treatmentCitations_approvedBy="felipe"IM.treatments_approvedBy="diego"checkinTime="1712169471054"checkinUser="felipe"docAuthor="Burrow, Carole Jan, Murphy, Michael & Turner, Susan"docDate="2023"docId="B21CD55BFFD7FFEA5AFB8DFBFBE327D1"docLanguage="en"docName="PaleoBios.40.4.1-32.pdf"docOrigin="PaleoBios 40 (1975)"docSource="http://dx.doi.org/10.5070/p940454153"docStyle="DocumentStyle:76F55B8832C4952BA7DD61B33E1F0E81.1:PaleoBios.2023-.journal_article"docStyleId="76F55B8832C4952BA7DD61B33E1F0E81"docStyleName="PaleoBios.2023-.journal_article"docStyleVersion="1"docTitle="Gomphonchoporus hoppei"docType="treatment"docVersion="6"lastPageNumber="9"masterDocId="4E25AD23FFDEFFE0596C8867FF9B270C"masterDocTitle="Late Silurian to earliest Devonian vertebrate biostratigraphy of the Birch Creek II section, Roberts Mountains, Nevada, U. S. A."masterLastPageNumber="32"masterPageNumber="1"pageNumber="8"updateTime="1717597860775"updateUser="ExternalLinkService"zenodo-license-document="CC-BY-NC-SA-4.0">
<mods:titleid="C3918FDFC21E0AA2D52792F530F1B6E4">Late Silurian to earliest Devonian vertebrate biostratigraphy of the Birch Creek II section, Roberts Mountains, Nevada, U. S. A.</mods:title>
<bibRefCitationid="5E2419BCFFD7FFE95D9F8DFBFA1522BA"author="Gross, W."box="[1267,1422,1436,1462]"pageId="9"pageNumber="8"pagination="91 - 161"refId="ref23372"refString="Gross, W. 1947. Die Agnathen und Acanthodier des obersilurischen Beyrichienkalks. Palaeontographica Abt. A 96: 91 - 161."type="journal article"year="1947">GROSS, 1947</bibRefCitation>
<figureCitationid="A28E78C8FFD7FFE95A078DD8FC6D22D5"box="[875,1014,1471,1497]"captionStart="Figure 3"captionStartId="12.[112,191,1493,1517]"captionTargetBox="[112,1520,272,1460]"captionTargetId="figure-277@12.[112,1520,272,1460]"captionTargetPageId="12"captionText="Figure 3. Poracanthodid and ischnacanthid acanthodian scales from Upper Silurian levels of the Birch Creek II section. A–E,?F,?G. Gomphonchoporus hoppei: A. UCR 949-1 (level 567.3') in crown view (from Supplement 1, fig. 24); B. UCR 944-11 (level 527.25') in laterocrown view; C, D. UCR 5439-2 (level 549') in anterocrown and laterocrown views; E. UCR 5439-3 (level 549') in basal view; F. UCR 5439-7 (level 549') in crown view; G. UCR 5439-1 (level 549') in anterocrown view. H–J. Zemlyacanthus menneri: UCR 10815-1, 2, 3 (level 556.5'), in crown views (from Supplement 1, fig. 22). M–P. Trundlelepis cervicostulata: K, L. UCR 10768-4 (level 518.3') in anterior and lateral views; M. UCR 944-17 (level 527.25') in crown view; N. UCR 944-3 (level 527.25') in crown view; O. UCR 944-23 (level 527.25'), vertical longitudinal thin section; P. UCR 944-22 (level 527.25'), horizontal thin section through crown. Q, R. Poracanthodidae gen., sp. indet. sensory line scale UCR 930-3 (level 395') in crown and posterior views. S-V. Gomphonchus sandelensis: S, T. UCR 10746-11 (level 430.5') in crown and lateral views; U,V. UCR 930-7 (level 395') in antero- and posterocrown views. W–Z. Gomphonchus mediocostatus: W. UCR 944-6 (level 527.25') in crown view; X. UCR 944-16 (level 527.25') in crown view; Y. UCR 942-1 (level 526') in crown view (from Supplement 1, fig. 20); Z. UCR 944-19 (level 527.25') in laterocrown view. Abbreviations: cgz=crown growth zones; dt=dentine tubules; h=hyphal borings; vc=vertical canals. Scale bars=0.1 mm, anterior of scale"figureDoi="http://doi.org/10.5281/zenodo.10913565"httpUri="https://zenodo.org/record/10913565/files/figure.png"pageId="9"pageNumber="8">FIG. 3A–3E</figureCitation>
,?3F,?3G;
<tableCitationid="773751F6FFD7FFE95D188DD8FB4D22D5"box="[1140,1238,1471,1497]"captionStart="Table 1"captionStartId="5.[112,179,1869,1893]"captionTargetBox="[120,1534,204,1847]"captionTargetId="graphics-72@5.[112,1519,193,1849]"captionTargetPageId="5"captionText="Table 1. Distribution of vertebrate and agnathan remains in the Birch Creek Section BCII, northern Roberts Mts. (Přidolí- Lochkovian; bold line indicates probable S/D boundary). Vertebrates are to the left above the upper horizontal line and agnathans are to the right. RP indicates Ross Parke samples. Number of elements: x 1-10, xx 11-50, xxx 51-100, xxxx>100."httpUri="http://table.plazi.org/id/6ECA34C5FFDBFFE5591C8F2AFA2520A9"pageId="9"pageNumber="8"tableUuid="6ECA34C5FFDBFFE5591C8F2AFA2520A9">TABLE 1</tableCitation>
<bibRefCitationid="5E2419BCFFD7FFE95DDE8E08FA042185"author="Vergoossen, J. M. J."box="[1202,1439,1647,1673]"pageId="9"pageNumber="8"pagination="231 - 251"refId="ref26647"refString="Vergoossen, J. M. J. 1999 a. Late Silurian fish microfossils from an East Baltic-derived erratic from Oosterhaule, with a description of new acanthodian taxa. Geologie en Minjbouw 78: 231 - 251."type="journal article"year="1999">Vergoossen 1999a</bibRefCitation>
<bibRefCitationid="5E2419BCFFD7FFE95D5C8EBEFAB721FE"author="Vergoossen, J. M. J."box="[1072,1324,1752,1779]"pageId="9"pageNumber="8"pagination="231 - 251"refId="ref26647"refString="Vergoossen, J. M. J. 1999 a. Late Silurian fish microfossils from an East Baltic-derived erratic from Oosterhaule, with a description of new acanthodian taxa. Geologie en Minjbouw 78: 231 - 251."type="journal article"year="1999">Vergoossen (1999a)</bibRefCitation>
<bibRefCitationid="5E2419BCFFD7FFE95CCB8E9BFC1A2035"author="Gross, W."pageId="9"pageNumber="8"pagination="91 - 161"refId="ref23372"refString="Gross, W. 1947. Die Agnathen und Acanthodier des obersilurischen Beyrichienkalks. Palaeontographica Abt. A 96: 91 - 161."type="journal article"year="1947">Gross 1947</bibRefCitation>
, pl. 24 fig. 7); from the Beyrichienkalk, northern
<bibRefCitationid="5E2419BCFFD4FFEA584D8937FE5C2666"author="Parkes, R."box="[289,455,335,362]"pageId="10"pageNumber="9"refId="ref25224"refString="Parkes, R. 1995. Late Silurian - Early Devonian vertebrate microremains from Nevada and southeastern Australia: biochronology, biogeography and application of novel histological techniques. Unpublished B. Sc. (Hons) thesis, Macquarie University, Sydney, NSW."type="book"year="1995">Parkes (1995</bibRefCitation>
<bibRefCitationid="5E2419BCFFD4FFEA589C89DDFD7026D8"author="Vergoossen, J. M. J."box="[496,747,441,468]"pageId="10"pageNumber="9"pagination="231 - 251"refId="ref26647"refString="Vergoossen, J. M. J. 1999 a. Late Silurian fish microfossils from an East Baltic-derived erratic from Oosterhaule, with a description of new acanthodian taxa. Geologie en Minjbouw 78: 231 - 251."type="journal article"year="1999">Vergoossen (1999a)</bibRefCitation>
, the type scales described and figured by
<bibRefCitationid="5E2419BCFFD4FFEA5B5E89BAFD5126FB"author="Gross, W."box="[562,714,477,503]"pageId="10"pageNumber="9"pagination="91 - 161"refId="ref23372"refString="Gross, W. 1947. Die Agnathen und Acanthodier des obersilurischen Beyrichienkalks. Palaeontographica Abt. A 96: 91 - 161."type="journal article"year="1947">Gross (1947</bibRefCitation>
,
<bibRefCitationid="5E2419BCFFD4FFEA5BB889BAFC8E26FB"author="Gross, W."box="[724,789,477,503]"pageId="10"pageNumber="9"pagination="1 - 82"refId="ref23439"refString="Gross, W. 1971. Downtonische und Dittonische Acanthodier-Reste des Ostseegebietes. Palaeontographica Abt. A 136: 1 - 82."type="journal article"year="1971">1971</bibRefCitation>
) were abraded, with delicate structures missing, in particular, the lateral areas of the posterior crown. For this reason,
<bibRefCitationid="5E2419BCFFD4FFEA59BE8A20FE55256D"author="Vergoossen, J. M. J."box="[210,462,582,609]"pageId="10"pageNumber="9"pagination="231 - 251"refId="ref26647"refString="Vergoossen, J. M. J. 1999 a. Late Silurian fish microfossils from an East Baltic-derived erratic from Oosterhaule, with a description of new acanthodian taxa. Geologie en Minjbouw 78: 231 - 251."type="journal article"year="1999">Vergoossen (1999a)</bibRefCitation>
. However, the type specimen is still reposited in the MB.f collection so those allocations are not valid. Being better preserved than the type scales, those from
(1999a, pl. 4.42–4.44) and have numerous ridges leading back from the anterior margin (
<figureCitationid="A28E78C8FFD4FFEA58DF8BC1FD9624CC"box="[435,525,934,960]"captionStart="Figure 3"captionStartId="12.[112,191,1493,1517]"captionTargetBox="[112,1520,272,1460]"captionTargetId="figure-277@12.[112,1520,272,1460]"captionTargetPageId="12"captionText="Figure 3. Poracanthodid and ischnacanthid acanthodian scales from Upper Silurian levels of the Birch Creek II section. A–E,?F,?G. Gomphonchoporus hoppei: A. UCR 949-1 (level 567.3') in crown view (from Supplement 1, fig. 24); B. UCR 944-11 (level 527.25') in laterocrown view; C, D. UCR 5439-2 (level 549') in anterocrown and laterocrown views; E. UCR 5439-3 (level 549') in basal view; F. UCR 5439-7 (level 549') in crown view; G. UCR 5439-1 (level 549') in anterocrown view. H–J. Zemlyacanthus menneri: UCR 10815-1, 2, 3 (level 556.5'), in crown views (from Supplement 1, fig. 22). M–P. Trundlelepis cervicostulata: K, L. UCR 10768-4 (level 518.3') in anterior and lateral views; M. UCR 944-17 (level 527.25') in crown view; N. UCR 944-3 (level 527.25') in crown view; O. UCR 944-23 (level 527.25'), vertical longitudinal thin section; P. UCR 944-22 (level 527.25'), horizontal thin section through crown. Q, R. Poracanthodidae gen., sp. indet. sensory line scale UCR 930-3 (level 395') in crown and posterior views. S-V. Gomphonchus sandelensis: S, T. UCR 10746-11 (level 430.5') in crown and lateral views; U,V. UCR 930-7 (level 395') in antero- and posterocrown views. W–Z. Gomphonchus mediocostatus: W. UCR 944-6 (level 527.25') in crown view; X. UCR 944-16 (level 527.25') in crown view; Y. UCR 942-1 (level 526') in crown view (from Supplement 1, fig. 20); Z. UCR 944-19 (level 527.25') in laterocrown view. Abbreviations: cgz=crown growth zones; dt=dentine tubules; h=hyphal borings; vc=vertical canals. Scale bars=0.1 mm, anterior of scale"figureDoi="http://doi.org/10.5281/zenodo.10913565"httpUri="https://zenodo.org/record/10913565/files/figure.png"pageId="10"pageNumber="9">Fig. 3A</figureCitation>
), whereas others have a shallow median sulcus running back from the anterior edge of the crown to the level of the lateral corners, and only a few short low ridges running back from the anterior margin (
<figureCitationid="A28E78C8FFD4FFEA583D8C54FE752341"box="[337,494,1075,1101]"captionStart="Figure 3"captionStartId="12.[112,191,1493,1517]"captionTargetBox="[112,1520,272,1460]"captionTargetId="figure-277@12.[112,1520,272,1460]"captionTargetPageId="12"captionText="Figure 3. Poracanthodid and ischnacanthid acanthodian scales from Upper Silurian levels of the Birch Creek II section. A–E,?F,?G. Gomphonchoporus hoppei: A. UCR 949-1 (level 567.3') in crown view (from Supplement 1, fig. 24); B. UCR 944-11 (level 527.25') in laterocrown view; C, D. UCR 5439-2 (level 549') in anterocrown and laterocrown views; E. UCR 5439-3 (level 549') in basal view; F. UCR 5439-7 (level 549') in crown view; G. UCR 5439-1 (level 549') in anterocrown view. H–J. Zemlyacanthus menneri: UCR 10815-1, 2, 3 (level 556.5'), in crown views (from Supplement 1, fig. 22). M–P. Trundlelepis cervicostulata: K, L. UCR 10768-4 (level 518.3') in anterior and lateral views; M. UCR 944-17 (level 527.25') in crown view; N. UCR 944-3 (level 527.25') in crown view; O. UCR 944-23 (level 527.25'), vertical longitudinal thin section; P. UCR 944-22 (level 527.25'), horizontal thin section through crown. Q, R. Poracanthodidae gen., sp. indet. sensory line scale UCR 930-3 (level 395') in crown and posterior views. S-V. Gomphonchus sandelensis: S, T. UCR 10746-11 (level 430.5') in crown and lateral views; U,V. UCR 930-7 (level 395') in antero- and posterocrown views. W–Z. Gomphonchus mediocostatus: W. UCR 944-6 (level 527.25') in crown view; X. UCR 944-16 (level 527.25') in crown view; Y. UCR 942-1 (level 526') in crown view (from Supplement 1, fig. 20); Z. UCR 944-19 (level 527.25') in laterocrown view. Abbreviations: cgz=crown growth zones; dt=dentine tubules; h=hyphal borings; vc=vertical canals. Scale bars=0.1 mm, anterior of scale"figureDoi="http://doi.org/10.5281/zenodo.10913565"httpUri="https://zenodo.org/record/10913565/files/figure.png"pageId="10"pageNumber="9">Figs. 3A–3D</figureCitation>
,?3F,?3G). The straight anterior edges of the crown meet at an acute angle. The posterior crown is formed of appositional growth zones, expressed on the surface as long slits paralleling the straight posterolateral edges of the crown, or with more anterior growth zones appearing to overlap the growth zone behind (
<figureCitationid="A28E78C8FFD4FFEA58E88D61FE78222C"box="[388,483,1286,1312]"captionStart="Figure 3"captionStartId="12.[112,191,1493,1517]"captionTargetBox="[112,1520,272,1460]"captionTargetId="figure-277@12.[112,1520,272,1460]"captionTargetPageId="12"captionText="Figure 3. Poracanthodid and ischnacanthid acanthodian scales from Upper Silurian levels of the Birch Creek II section. A–E,?F,?G. Gomphonchoporus hoppei: A. UCR 949-1 (level 567.3') in crown view (from Supplement 1, fig. 24); B. UCR 944-11 (level 527.25') in laterocrown view; C, D. UCR 5439-2 (level 549') in anterocrown and laterocrown views; E. UCR 5439-3 (level 549') in basal view; F. UCR 5439-7 (level 549') in crown view; G. UCR 5439-1 (level 549') in anterocrown view. H–J. Zemlyacanthus menneri: UCR 10815-1, 2, 3 (level 556.5'), in crown views (from Supplement 1, fig. 22). M–P. Trundlelepis cervicostulata: K, L. UCR 10768-4 (level 518.3') in anterior and lateral views; M. UCR 944-17 (level 527.25') in crown view; N. UCR 944-3 (level 527.25') in crown view; O. UCR 944-23 (level 527.25'), vertical longitudinal thin section; P. UCR 944-22 (level 527.25'), horizontal thin section through crown. Q, R. Poracanthodidae gen., sp. indet. sensory line scale UCR 930-3 (level 395') in crown and posterior views. S-V. Gomphonchus sandelensis: S, T. UCR 10746-11 (level 430.5') in crown and lateral views; U,V. UCR 930-7 (level 395') in antero- and posterocrown views. W–Z. Gomphonchus mediocostatus: W. UCR 944-6 (level 527.25') in crown view; X. UCR 944-16 (level 527.25') in crown view; Y. UCR 942-1 (level 526') in crown view (from Supplement 1, fig. 20); Z. UCR 944-19 (level 527.25') in laterocrown view. Abbreviations: cgz=crown growth zones; dt=dentine tubules; h=hyphal borings; vc=vertical canals. Scale bars=0.1 mm, anterior of scale"figureDoi="http://doi.org/10.5281/zenodo.10913565"httpUri="https://zenodo.org/record/10913565/files/figure.png"pageId="10"pageNumber="9">Fig. 3A</figureCitation>
). Few of the BC II scales have the posterolateral edges preserved, but at least one scale (
<bibRefCitationid="5E2419BCFFD4FFEA59D28D2BFEC2226B"author="Parkes, R."box="[190,345,1356,1383]"pageId="10"pageNumber="9"refId="ref25224"refString="Parkes, R. 1995. Late Silurian - Early Devonian vertebrate microremains from Nevada and southeastern Australia: biochronology, biogeography and application of novel histological techniques. Unpublished B. Sc. (Hons) thesis, Macquarie University, Sydney, NSW."type="book"year="1995">Parkes 1995</bibRefCitation>
, fig. 33.5, 33.6) has the close-set denticulations that are visible on the well-preserved scales figured by
<bibRefCitationid="5E2419BCFFD4FFEA599C8DF4FE7C22A1"author="Vergoossen, J. M. J."box="[240,487,1427,1453]"pageId="10"pageNumber="9"pagination="231 - 251"refId="ref26647"refString="Vergoossen, J. M. J. 1999 a. Late Silurian fish microfossils from an East Baltic-derived erratic from Oosterhaule, with a description of new acanthodian taxa. Geologie en Minjbouw 78: 231 - 251."type="journal article"year="1999">Vergoossen (1999a)</bibRefCitation>
. The scale neck is concave all round, and of comparable height to the base, with a marked rim separating neck and base. A strong median ridge rises from the posterior base towards the lower surface of the crown (
<figureCitationid="A28E78C8FFD4FFEA58EE8E47FE662136"box="[386,509,1568,1594]"captionStart="Figure 3"captionStartId="12.[112,191,1493,1517]"captionTargetBox="[112,1520,272,1460]"captionTargetId="figure-277@12.[112,1520,272,1460]"captionTargetPageId="12"captionText="Figure 3. Poracanthodid and ischnacanthid acanthodian scales from Upper Silurian levels of the Birch Creek II section. A–E,?F,?G. Gomphonchoporus hoppei: A. UCR 949-1 (level 567.3') in crown view (from Supplement 1, fig. 24); B. UCR 944-11 (level 527.25') in laterocrown view; C, D. UCR 5439-2 (level 549') in anterocrown and laterocrown views; E. UCR 5439-3 (level 549') in basal view; F. UCR 5439-7 (level 549') in crown view; G. UCR 5439-1 (level 549') in anterocrown view. H–J. Zemlyacanthus menneri: UCR 10815-1, 2, 3 (level 556.5'), in crown views (from Supplement 1, fig. 22). M–P. Trundlelepis cervicostulata: K, L. UCR 10768-4 (level 518.3') in anterior and lateral views; M. UCR 944-17 (level 527.25') in crown view; N. UCR 944-3 (level 527.25') in crown view; O. UCR 944-23 (level 527.25'), vertical longitudinal thin section; P. UCR 944-22 (level 527.25'), horizontal thin section through crown. Q, R. Poracanthodidae gen., sp. indet. sensory line scale UCR 930-3 (level 395') in crown and posterior views. S-V. Gomphonchus sandelensis: S, T. UCR 10746-11 (level 430.5') in crown and lateral views; U,V. UCR 930-7 (level 395') in antero- and posterocrown views. W–Z. Gomphonchus mediocostatus: W. UCR 944-6 (level 527.25') in crown view; X. UCR 944-16 (level 527.25') in crown view; Y. UCR 942-1 (level 526') in crown view (from Supplement 1, fig. 20); Z. UCR 944-19 (level 527.25') in laterocrown view. Abbreviations: cgz=crown growth zones; dt=dentine tubules; h=hyphal borings; vc=vertical canals. Scale bars=0.1 mm, anterior of scale"figureDoi="http://doi.org/10.5281/zenodo.10913565"httpUri="https://zenodo.org/record/10913565/files/figure.png"pageId="10"pageNumber="9">Fig. 3A, B</figureCitation>
), and the undersurface of the posterior crown (
<figureCitationid="A28E78C8FFD4FFEA58CD8E24FE672151"box="[417,508,1603,1629]"captionStart="Figure 3"captionStartId="12.[112,191,1493,1517]"captionTargetBox="[112,1520,272,1460]"captionTargetId="figure-277@12.[112,1520,272,1460]"captionTargetPageId="12"captionText="Figure 3. Poracanthodid and ischnacanthid acanthodian scales from Upper Silurian levels of the Birch Creek II section. A–E,?F,?G. Gomphonchoporus hoppei: A. UCR 949-1 (level 567.3') in crown view (from Supplement 1, fig. 24); B. UCR 944-11 (level 527.25') in laterocrown view; C, D. UCR 5439-2 (level 549') in anterocrown and laterocrown views; E. UCR 5439-3 (level 549') in basal view; F. UCR 5439-7 (level 549') in crown view; G. UCR 5439-1 (level 549') in anterocrown view. H–J. Zemlyacanthus menneri: UCR 10815-1, 2, 3 (level 556.5'), in crown views (from Supplement 1, fig. 22). M–P. Trundlelepis cervicostulata: K, L. UCR 10768-4 (level 518.3') in anterior and lateral views; M. UCR 944-17 (level 527.25') in crown view; N. UCR 944-3 (level 527.25') in crown view; O. UCR 944-23 (level 527.25'), vertical longitudinal thin section; P. UCR 944-22 (level 527.25'), horizontal thin section through crown. Q, R. Poracanthodidae gen., sp. indet. sensory line scale UCR 930-3 (level 395') in crown and posterior views. S-V. Gomphonchus sandelensis: S, T. UCR 10746-11 (level 430.5') in crown and lateral views; U,V. UCR 930-7 (level 395') in antero- and posterocrown views. W–Z. Gomphonchus mediocostatus: W. UCR 944-6 (level 527.25') in crown view; X. UCR 944-16 (level 527.25') in crown view; Y. UCR 942-1 (level 526') in crown view (from Supplement 1, fig. 20); Z. UCR 944-19 (level 527.25') in laterocrown view. Abbreviations: cgz=crown growth zones; dt=dentine tubules; h=hyphal borings; vc=vertical canals. Scale bars=0.1 mm, anterior of scale"figureDoi="http://doi.org/10.5281/zenodo.10913565"httpUri="https://zenodo.org/record/10913565/files/figure.png"pageId="10"pageNumber="9">Fig. 3E</figureCitation>
) shows the wide canal openings that typify poracanthodid scales. Some scales with relatively long aligned slits on the posterior crown surface (
<figureCitationid="A28E78C8FFD4FFEA59BB8ECBFEDD21CB"box="[215,326,1708,1735]"captionStart="Figure 3"captionStartId="12.[112,191,1493,1517]"captionTargetBox="[112,1520,272,1460]"captionTargetId="figure-277@12.[112,1520,272,1460]"captionTargetPageId="12"captionText="Figure 3. Poracanthodid and ischnacanthid acanthodian scales from Upper Silurian levels of the Birch Creek II section. A–E,?F,?G. Gomphonchoporus hoppei: A. UCR 949-1 (level 567.3') in crown view (from Supplement 1, fig. 24); B. UCR 944-11 (level 527.25') in laterocrown view; C, D. UCR 5439-2 (level 549') in anterocrown and laterocrown views; E. UCR 5439-3 (level 549') in basal view; F. UCR 5439-7 (level 549') in crown view; G. UCR 5439-1 (level 549') in anterocrown view. H–J. Zemlyacanthus menneri: UCR 10815-1, 2, 3 (level 556.5'), in crown views (from Supplement 1, fig. 22). M–P. Trundlelepis cervicostulata: K, L. UCR 10768-4 (level 518.3') in anterior and lateral views; M. UCR 944-17 (level 527.25') in crown view; N. UCR 944-3 (level 527.25') in crown view; O. UCR 944-23 (level 527.25'), vertical longitudinal thin section; P. UCR 944-22 (level 527.25'), horizontal thin section through crown. Q, R. Poracanthodidae gen., sp. indet. sensory line scale UCR 930-3 (level 395') in crown and posterior views. S-V. Gomphonchus sandelensis: S, T. UCR 10746-11 (level 430.5') in crown and lateral views; U,V. UCR 930-7 (level 395') in antero- and posterocrown views. W–Z. Gomphonchus mediocostatus: W. UCR 944-6 (level 527.25') in crown view; X. UCR 944-16 (level 527.25') in crown view; Y. UCR 942-1 (level 526') in crown view (from Supplement 1, fig. 20); Z. UCR 944-19 (level 527.25') in laterocrown view. Abbreviations: cgz=crown growth zones; dt=dentine tubules; h=hyphal borings; vc=vertical canals. Scale bars=0.1 mm, anterior of scale"figureDoi="http://doi.org/10.5281/zenodo.10913565"httpUri="https://zenodo.org/record/10913565/files/figure.png"pageId="10"pageNumber="9">Fig. 3F, G</figureCitation>
<bibRefCitationid="5E2419BCFFD4FFEA59178F71FEFB203C"author="Valiukevicius, J. J."box="[123,352,1814,1840]"pageId="10"pageNumber="9"refId="ref26180"refString="Valiukevicius, J. J. 1992. First articulated Poracanthodes from the Lower Devonian of Severnaya Zemlya. Pp. 193 - 214 in E. Mark-Kurik (ed.). Fossil Fishes as Living Animals. Academia 1, Academy of Sciences of Estonia, Tallinn."type="book"year="1992">Valiukevičius 1992</bibRefCitation>
, pl. 10.6–10.8), but only have straight slits and pore openings in the posterior area of the crown, rather than zigzag slits extending close to the anterior margin that characterize
