Rhinoscymnus clarki
Cappetta, Morrison & Adnet, 2019
Classification: Elasmobranchii Squaliformes Somniosidae
Reference of the original description
A shark fauna from the Campanian of Hornby Island, British Columbia, Canada: an insight into the diversity of Cretaceous deep-water assemblages. Historical Biology, 33(8), 1121–1182
A shark fauna from the Campanian of Hornby Island, British Columbia, Canada: an insight into the diversity of Cretaceous deep-water assemblages. Historical Biology, 33(8), 1121–1182
Description:
Citation: Rhinoscymnus clarki Cappetta, Morrison & Adnet, 2019: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 08/2026
Description
Original diagnosis after Cappetta, Morrison & Adnet, 2019 [27810]: Species with a sharp triangular and strongly bent distally cusp. Long mesial cutting edge practically straight and smooth. Distal edge is much shorter and very oblique. In labial view, the apron is very flat, with a not very well-marked limit. Presence of a distal heel not very high. In lingual view, the distal heel is more delimited and not very high and the mesial edge abruptly to join a salient spur. There is a strong horizontal lingual protuberance located mid height. This protuberance is thicker distally where it differentiates a bulge overhanging an articular facet beginning under the heel, curved and narrowing distally. In lingual view, a deep elliptical axial foramen stops the protuberance with a bifid and short uvula surrounding the apex of the foramen. On both sides of the uvula and above the protuberance, there is a distinct hollow where a circular foramen opens. Below the central basal foramen, there is a shallow furrow joining a short basal notch cutting the basal margin of the root. The labial face of the root bears some foramina of varied sizes and irregularly opening close the limit of the apron.
In labial (or lingual) view, the mesial outline of the tooth is characterised by a salient spur and a broad rounded sinuosity below. The distal outline is more developed and regularly convex.
Original diagnosis after Cappetta, Morrison & Adnet, 2019 [27810]: Species with a sharp triangular and strongly bent distally cusp. Long mesial cutting edge practically straight and smooth. Distal edge is much shorter and very oblique. In labial view, the apron is very flat, with a not very well-marked limit. Presence of a distal heel not very high. In lingual view, the distal heel is more delimited and not very high and the mesial edge abruptly to join a salient spur. There is a strong horizontal lingual protuberance located mid height. This protuberance is thicker distally where it differentiates a bulge overhanging an articular facet beginning under the heel, curved and narrowing distally. In lingual view, a deep elliptical axial foramen stops the protuberance with a bifid and short uvula surrounding the apex of the foramen. On both sides of the uvula and above the protuberance, there is a distinct hollow where a circular foramen opens. Below the central basal foramen, there is a shallow furrow joining a short basal notch cutting the basal margin of the root. The labial face of the root bears some foramina of varied sizes and irregularly opening close the limit of the apron.
In labial (or lingual) view, the mesial outline of the tooth is characterised by a salient spur and a broad rounded sinuosity below. The distal outline is more developed and regularly convex.
References
Bioluminescence and repeated deep-sea colonization shaped the diversification and body size evolution of squaliform sharks. Proceedings of the Royal Society B-Biological Sciences, 292(2042), Article 20242932
DOI: 10.1098/rspb.2024.2932
Global impact and selectivity of the Cretaceous-Paleogene mass extinction among sharks, skates, and rays. Science, 379, 802–806
DOI: 10.1126/science.abn2080
A shark fauna from the Campanian of Hornby Island, British Columbia, Canada: an insight into the diversity of Cretaceous deep-water assemblages. Historical Biology, 33(8), 1121–1182
DOI: 10.1080/08912963.2019.1681421

Bioluminescence and repeated deep-sea colonization shaped the diversification and body size evolution of squaliform sharks. Proceedings of the Royal Society B-Biological Sciences, 292(2042), Article 20242932
DOI: 10.1098/rspb.2024.2932

Global impact and selectivity of the Cretaceous-Paleogene mass extinction among sharks, skates, and rays. Science, 379, 802–806
DOI: 10.1126/science.abn2080

A shark fauna from the Campanian of Hornby Island, British Columbia, Canada: an insight into the diversity of Cretaceous deep-water assemblages. Historical Biology, 33(8), 1121–1182
DOI: 10.1080/08912963.2019.1681421







