Cladodoides cf. wildungensis
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publication ID |
https://doi.org/ 10.26879/583 |
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persistent identifier |
https://treatment.plazi.org/id/ED189025-6066-FF8F-FC2F-F9B36C9F9596 |
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treatment provided by |
Felipe |
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scientific name |
Cladodoides cf. wildungensis |
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Figure 4.8 View FIGURE 4 -12
Material. Three teeth from sample 198404, one tooth from sample 198480, two teeth from sample TS-1, Laurel Formation, Laurel Downs, Tournaisian.
Description. The pentacuspid crown comprises a large triangular central cusp with a pair of distally diverging lateral cusps and small (approximately two thirds the size of the lateral cusps) intermediate cusplets ( Figure 4.8 View FIGURE 4 -12). Cusp faces are ornamented in coarse, predominantly parallel ridges converging toward the cusp apex ( Figure 4.8, 4.12 View FIGURE 4 ). The labial face of the central cusp is flattened with a slight baso-labial depression. The base is lenticular in outline ( Figure 4.9 View FIGURE 4 ) and extends furthest in front of the central cusp. The crown-base interface is marked by a low arch along the labial face ( Figure 4.8 View FIGURE 4 ). The lateral end of the base extends beyond the crown in most specimens; however, this is significantly less extended in one specimen ( Figure 4.12 View FIGURE 4 ) A row of small pores is present along the crown base interface on the labial side. An ovoid button extends between the distal margins of the intermediate cusplets and is positioned centrally along the occlusal edge of the baso-lingual rim. The baso-labial thickening lies between the intermediate cusps and does not protrude far lingually ( Figure 4.10, 4.12 View FIGURE 4 ).
Remarks. The teeth bear a resemblance to the teeth originally described as Stethacanthus resistens by Ginter (2002) and later synonymised with Cladodoides wildungensis Jaekel, 1921 (Ginter et al., 2010). The teeth from the Canning Basin share the pentacuspid crown and strong divergence of the lateral cusps seen in the smaller tooth forms of C. wildungensis (Ginter et al., 2010, figure 66F). The basal features are also comparable, with an elongated lenticular base extending beyond the crown foot as well as possessing the mesio-distally elongated lingual button. Despite these similarities, the cusps on the Canning Basin teeth appear shorter and more robust than those seen in teeth attributed to C. wildungensis , including the holotype (Ginter et al., 2010, figure 66). Similar teeth with shorter cusps are evident in a tooth from the Famennian of north-western Iran ( Hampe, 2000, plate 2.1-4). Whether these Carboniferous forms belong to C. wildungensis is difficult to determine given the limited number of teeth recovered.
Cladodontomorphi indet. sp.
Figure 5.1-5 View FIGURE 5
Material. One tooth from sample 198404, Laurel Formation, Laurel Downs, Tournaisian.
Description. Asymmetrical tooth comprising five cusps with a large laterally inclined medial cusp and a pair of diverging lateral cusps approximately twice the size of the intermediate cusplets ( Figure 5.1 View FIGURE 5 ). There are fine ridges on the cusp faces with bifurcating ridges on the basal margins of the lateral cusps ( Figure 5.1-3 View FIGURE 5 ). The labial face of the crown is concave at the base with a row of small pores along the base-crown limit. The lingual extension of the base is short and almost trapezoid in outline, extending furthest between the mesial margins of the lateral cusps ( Figure 5.4-5 View FIGURE 5 ). There is a slight lateral extension of the base where it forms a laterally directed point ( Figure 5.4 View FIGURE 5 ). The lingual torus hosts a highly elongate ridge, which extends between the inner margins of lateral cusps and bears six large pore openings along the lingual face. The oro-lingual ridge is thickened at its termination point on one distal end and gradually reduces its size at the other ( Figure 5.5 View FIGURE 5 ) The baso-labial shelf is thickest between the accessory cusps, becoming less distinct at one distal margin as opposed to thickening at the other end ( Figure 5.3-4 View FIGURE 5 ). The underside of the tooth bears a shallow depression under the lingual torus that deepens below the main cusp ( Figure 5.4 View FIGURE 5 ).
Remarks. This tooth bears a few features associated with the genus Cladodus . These include a central cusp, which is short and triangular in form, as well as an elongate baso-labial shelf and long oro-lingual ridge. The tooth resembles Cladodus marginatus Agassiz, 1843 (figured in Duffin and Ginter, 2006, figure 3A-G) with its broad, robust based central cusp directed distally to one side. In addition, the central cusp is biconvex apart from the baso-labial portion where a shallow depression develops. In contrast to C. marginatus , the tooth here bears much finer ridges that cover the entirety of each cusp. In C. marginatus the ridges terminate approximately halfway up the cusp from the crown-base interface, with the majority of the upper central cusp surface remaining smooth.
Ctenacanthiform gen. et sp. indet. 1
Figure 5.6 View FIGURE 5 -11
Material. Three teeth from sample 198404, one tooth from sample 198480, four teeth from sample TS-1, Laurel Formation, Laurel Downs, Tournaisian.
Description. The tooth crown comprises a bulbous central cusp flanked by a pair of intermediate cusplets and a pair of lateral cusps diverging distally from the crown centre ( Figure 5.6-8 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 ). The intermediate cusplets erupt from a more labial position on the crown ( Figure 5.9 View FIGURE 5 -11) and are strongly fused mesially and distally with the neighbouring cusps. Both cusp faces bear ridges, rarely bifurcating at the base. The base forms a lenticular outline, extending lingually and, in some specimens, mesio-distally beyond the crown base ( Figure 5.6 View FIGURE 5 ). The lingual face of the base forms a steep angle between the lingual margin and the crown-base interface. In some specimens the basal height along the lingual face exceeds that of the crown. An oro-lingual ridge is often poorly developed; however, a series of canals can be found on some specimens, running from the lingual edge of the oro-lingual ridge to almost the crown base interface ( Figure 5.6 View FIGURE 5 ). A row of foramina along an elongate baso-labial shelf extend between the far lateral cusps ( Figure 5.9 View FIGURE 5 ).
Remarks. The tooth crowns are quite distinct in comparison to other cladodont type teeth in that the cusps are highly fused, up to two-thirds of the intermediate cusps with the lateral and central cusps ( Figure 5.9, 5.11 View FIGURE 5 ). Low profiled and similarly fused teeth belonging to Tamiobatis vetustus Eastman, 1897 were recovered from the Cleveland Shale of Ohio, USA ( Williams, 1998, figure 5E-F). Williams (1998) suggested these teeth represent the posterior teeth of the shark thereby indicating an unusual degree of heterodonty in this group of sharks. Whether this explains the unusually compact nature of the teeth described here is unclear. The differences in mesio-distal elongation, suggests these teeth occupy a range of positions in the jaw rather than just representing the posterior teeth of one species. The small sample size makes it difficult to correlate any impacts of ontogeny on tooth form. However, a comparison between the smallest tooth ( Figure 5.7 View FIGURE 5 ) and the largest tooth ( Figure 5.6 View FIGURE 5 ), suggests the highly compacted nature of the cusps is not a feature of either juvenile or adult teeth but is a unique character for this species.
Ctenacanthiform fam. gen. et sp. indet. 2
Figure 5.12 View FIGURE 5 -15
Material. 1 partial tooth from sample TS-1, Laurel Formation, Laurel Downs, Tournaisian.
Description. Only a small distal portion of the central cusp and part of the lingual torus are preserved ( Figure 5.12 View FIGURE 5 -15). The remnant of a large central cusp as well as the basal outline of a lateral cusp and intermediate cusplet can be detected. The baso-lingual face of the lateral cusp is approximately twice the size of the basal outline of the intermediate cusplet ( Figure 5.13 View FIGURE 5 ). Approximately one-third of the distal side of the central cusp is preserved. The basal part of the central cusp shows a slight convexity of the lingual face, whereas the labial face is flattened. In unabraded areas, the lingual faces of both the central and lateral cusps bear thin vertical striae ( Figure 5.12 View FIGURE 5 -13). The distal limit of a baso-labial depression can be seen on the central cusp ( Figure 5.14 View FIGURE 5 ). A row of faint foramina runs along the crown-base interface on the labial side of the tooth. The base extends lingually with the preserved part of the crenulated lingual rim showing a gentle curvature ( Figure 5.15 View FIGURE 5 ). Part of a well-defined, elongate oro-lingual button is positioned midway between the crown base and the lingual margin and extends from the broken face of the tooth to the base of the intermediate cusp. A thickened but incomplete baso-labial shelf lies between the broken edge of the distal margin of the central cusp and the mesial margin of the lateral cusp.
Remarks. The small fragment of the tooth does not preserve many of the diagnostic features in their entirety and makes any in depth comparisons difficult. The preserved end of the baso-labial shelf extends to the basal part of the lateral cusp and appears slightly thickened. The preserved section of the oro-lingual ridge is straight and extends to the inner edge of the lateral cusp base. These features indicate affinities to the Ctenacanthiforms. The oro-lingual button on many Cladodus terrelli Newberry, 1889 teeth is similar in shape and positioned centrally on the lingual torus, extending between the inner margins of the lateral cusps. The thin nature of the baso-lingual margin and vertical ridges are similar to those on the teeth of Cladodus terrelli .
Cohort EUSELACHII Hay, 1902
Superfamily PROTACRODONTOIDEA Zangerl, 1981
Family PROTACRODONTIDAE Cappetta, Duffin and Zidek, 1993
Genus PROTACRODUS Jaekel, 1925
Type Species. Protacrodus vestustus Jaekel, 1921
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.