<taxonomicNameid="37874D380D42FF8FFCBC74F68518A2CB"authorityName="Valiukevičius"authorityYear="2004"box="[812,1136,1456,1485]"class="Acanthodii"family="Ischnacanthidae"genus="Rohonilepis"higherTaxonomySource="GBIF"kingdom="Animalia"order="Ischnacanthida"pageId="8"pageNumber="155"phylum="Chordata"rank="species"species="breviornatus"status="gen. et sp. nov.">
<taxonomicNameLabelid="D9C057D20D42FF8FFBE874F78452A2CB"box="[1144,1338,1457,1485]"pageId="8"pageNumber="155"rank="species">gen. et sp. nov.</taxonomicNameLabel>
<figureCitationid="68BC2A3E0D42FF8FFCBC749E820EA2E8"box="[812,870,1496,1518]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="8"pageNumber="155">Fig. 8</figureCitation>
<figureCitationid="68BC2A3E0D42FF8FFB2B74B9846FA113"box="[1211,1287,1535,1557]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="8"pageNumber="155">Fig. 8C</figureCitation>
with tiny scales sculptured by 6 to 10 short, sharp, symmetrical sub−parallel anterior ridges turning anteriorly toward the neck−base junction. The two longest posteriorly pointing ridges can form an elevated medial area separating narrow, lowered lateral folds. Crown dentine contains medium−branched linear ascending and simple widened radial vascular canals over the flat−pyramidal base, that is composed of dense acellular bone.
<taxonomicNameid="37874D380D43FF8EFF34773280FFA181"authorityName="Valiukevičius"authorityYear="2004"box="[164,407,1652,1671]"class="Acanthodii"family="Ischnacanthidae"genus="Bracteatacanthus"higherTaxonomySource="GBIF"kingdom="Animalia"order="Ischnacanthiformes"pageId="9"pageNumber="156"phylum="Chordata"rank="species"species="assiduus"status="gen. et sp. nov.">
<taxonomicNameLabelid="D9C057D20D43FF8EFE0C7733834CA18E"box="[412,548,1653,1672]"pageId="9"pageNumber="156"rank="species">gen. et sp. nov.</taxonomicNameLabel>
. The same scale, detail of the right part. Scale bars 0.1 mm. Nida−44 borehole, depth 1213.0 m. Upper Silurian, Pridoli, Rietavas Beds of the Jūra Formation.
<quantityid="377F9B5E0D43FF8EFDC076D5826BA0AC"box="[592,771,1939,1963]"metricMagnitude="-4"metricUnit="m"metricValue="3.0"metricValueMax="3.8"metricValueMin="2.2"pageId="9"pageNumber="156"unit="mm"value="0.3"valueMax="0.38"valueMin="0.22">0.22 to 0.38 mm</quantity>
. The crown plate is horizontal, with up to one−third of the posterior unsculptured part overhanging the base. A quarter to one−third of the crown length has 6 to 10 short, sharp anterior ridges with a symmetrical profile, which fade posteriorly. Crown ridges may be straight (
<figureCitationid="68BC2A3E0D43FF8EFB10762985BFA08E"box="[1152,1239,1903,1928]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="9"pageNumber="156">Fig. 8D</figureCitation>
<figureCitationid="68BC2A3E0D43FF8EFC6376D68506A0AE"box="[1011,1134,1936,1961]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="9"pageNumber="156">Fig. 8B, C</figureCitation>
). The holotype−like specimens, with sub−parallel ridges are more abundant in samples studied, however, scales with almost parallel ridges also are known. Ridges are characteristically downwardly sloped anteriorly, sometimes reaching the base of the neck. Grooves between ridges are moderately deep and wide. Some scales have narrow lowered lateral ledges (
<figureCitationid="68BC2A3E0D40FF8DFE0176D7836EA0AC"box="[401,518,1937,1962]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="10"pageNumber="157">Fig. 8A, C</figureCitation>
), separated from the remainder of the crown by the two longest, posteriorly pointing ridges. Moderately high to low neck usually has linear rows of pores. The scale base slightly protrudes beyond the crown antero−laterally, but may be also displaced far in advance of the anterior margin of the crown.
<taxonomicNameid="37874D380D40FF8DFF3B77E380FBA1BE"authorityName="Valiukevičius"authorityYear="2004"box="[171,403,1701,1720]"class="Acanthodii"family="Ischnacanthidae"genus="Rohonilepis"higherTaxonomySource="GBIF"kingdom="Animalia"order="Ischnacanthida"pageId="10"pageNumber="157"phylum="Chordata"rank="species"species="breviornatus"status="gen. et sp. nov.">
<taxonomicNameLabelid="D9C057D20D40FF8DFE0B77E08345A1BF"box="[411,557,1702,1721]"pageId="10"pageNumber="157"rank="species">gen. et sp. nov.</taxonomicNameLabel>
<figureCitationid="68BC2A3E0D41FF8CFDFA71A183D7A606"box="[618,703,231,256]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="11"pageNumber="158">Fig. 8F</figureCitation>
<figureCitationid="68BC2A3E0D41FF8CFE8B70038006A658"box="[283,366,325,350]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="11"pageNumber="158">Fig. 8E</figureCitation>
<figureCitationid="68BC2A3E0D41FF8CFEFE7014801FA665"box="[366,375,338,355]"captionStart="Fig"captionStartId="1.[102,135,1919,1938]"captionTargetBox="[110,1473,1208,1887]"captionTargetId="figure-398@1.[105,1482,1203,1891]"captionTargetPageId="1"captionText="Fig. 2. Vesperalia perplexa gen. et sp. nov. SEM micrographs, trunk scales except for F, head? scale, crown views, anterior upwards: holotype, LIGG 25−A−2413 (A), LIGG 25−A−2416 (B), LIGG 25−A−2417 (C), LIGG 25−A−2418 (D), LIGG 25−A−2420 (E), LIGG 25−A−2422 (F), LIGG 25−A−2421 (G), LIGG 25−A−2414(H). Scalebars0.1 mm.Nida−44borehole, depth1213.0 m(A, E–H) andStoniškiai−1borehole, depth1211.0–1217.0 m(B–D). Upper Silurian, Pridoli, Rietavas Beds of the Jūra Formation."figureDoi="http://doi.org/10.5281/zenodo.13406158"httpUri="https://zenodo.org/record/13406158/files/figure.png"pageId="11"pageNumber="158">
, F) of ascending and other vascular canals are visible. Ascending canals are moderately branched and mostly linear along growth lamellae. Radial vascular canals are simple and located just over the basal surface (
<figureCitationid="68BC2A3E0D41FF8CFD2070E28269A6BA"box="[688,769,420,445]"captionStart="Fig"captionStartId="10.[102,135,1701,1720]"captionTargetBox="[107,1482,225,1674]"captionTargetId="figure-122@10.[104,1483,225,1673]"captionTargetPageId="10"captionText="Fig. 8. Rohonilepis breviornatus gen. et sp. nov. A–D. SEM micrographs of scales, crown views, anterior upwards. A. LIGG 25−A−2457. B. LIGG 25−A−2458. C. Holotype, LIGG 25−A−2459. D. LIGG 25−A−2461. E, F. Microstructure of scales in vertical longitudinal sections. E1. Thin section LIGG 3726, general view. E2. Detail of the upper right crown part of the same scale. F. Thin section LIGG 3727. Scale bars 0.1 mm. Kurtuvėnai−162 borehole, depth 1103.0 m. Upper Silurian, Ludlow, Ventspils Formation."figureDoi="http://doi.org/10.5281/zenodo.13406189"httpUri="https://zenodo.org/record/13406189/files/figure.png"pageId="11"pageNumber="158">Fig. 8F</figureCitation>
, right side). Durodentine has not been definitely recognized, but may be present. Acellular basal bone is dense and forms a flat−pyramid below the crown.
, as histologically they both have many characters in common. The latter is distinguished by the peculiar arrangement and position of radial vascular canals in the dentine of the crown, that is definitely not present in
<bibRefCitationid="94164B4A0D41FF8CFEC672A480B7A4FC"author="Marss, T."box="[342,479,994,1018]"pageId="11"pageNumber="158"pagination="17 - 41"refId="ref9224"refString="Marss, T. 1997. Vertebrates of the Pridoli and Silurian - Devonian boundary beds in Europe. Modern Geology 21: 17 - 41."type="journal article"year="1997">Märss 1997</bibRefCitation>
: pl. 7: 3, 10).
<bibRefCitationid="94164B4A0D41FF8CFD1572A481C7A31F"author="Vergoossen, J. M. J."pageId="11"pageNumber="158"pagination="93 - 158"refId="ref9479"refString="Vergoossen, J. M. J. 2002. Late Silurian fish microfossils from Ramsasa (sites D and " south of church "), Skane, south Sweden. Scripta Geologica 123: 93 - 158."type="journal article"year="2002">Vergoossen (2002)</bibRefCitation>
gen. et sp. indet. that are similar but not as well preserved as the material figured here, but suggest, that some comparable varieties of scales might also be present in southern