Edited by Anomotodon
Species: 'H.' upnikensis
Author Citation Dalinkevicius, 1935
Albian sediments of Kanev region, Ukraine
Collector: Tim Sokolskyi
Acquired by: Field Collection
Melanchyn potik ravine, Kanev national reserve
A - lateral;
B, C, D - anteriors.
Anterior teeth have typical of Heterodontus V-shaped root and marked cutting edge. Unlike H. canaliculatus anteriors, anteriors of ‘H.’ upnikensis have more convex labial side (so that cutting edge is situated in the middle of the lateral surface) and no lateral cusplets. Crown generally widens near the base, so most teeth have regular triangle shape of a labial face. Teeth located closer to symphysis display more mesiodistally compressed crowns. Enamel is smooth on both faces. Lateral teeth are also different from H. canaliculatus: they have lower and shorter central occlusal ridge and lateral ridges are highly anostomosed on both sides, so that complete tooth ornamentation has a net-like appearance.
‘Heterodontus’ upnikensis is an enigmatic species. No associated tooth set has been found yet, consequently it is impossible to tell that a given set of laterals actually belong to ‘H.’ upnikensis. There is a possibility that lateral teeth described here as ‘H.’ upnikensis here belong to another Heterodontus species not represented by anteriors in Kanev collection. They were assigned to this species because there is generally some degree of tooth plan similarity between anteriors and laterals of the same species. Laterals described here have: 1) relatively weak and short central occlusal ridge; this trait is similar to ‘H.’ upnikensis shorter cutting edge because of lateral cusplet absence; 2) more bilateraly symmetrical crown shape and ornamentation across the central occlusal ridge than in H. canaliculatus; this feature is analogous to relatively equal thickness of labial and lingual face on ‘H.’ upnikensis anterior teeth. Also, anteriors of ‘H.’ upnikensis are a lot more common in studied locations than H. canaliculatus, and the same trend applies to two found Heterodontus lateral teeth morphotypes with H. canaliculatus teeth being a lot scarcer.
Edited by Anomotodon