Search the Community
Showing results for tags 'ophthalmosauridae'.
-
Pliosaur tooth, or ophthalmosaurid ichthyosaur (Stary Oskol)
pachy-pleuro-whatnot-odon posted a topic in Fossil ID
Hi all, First off, this is not my fossil (though I own a large crow of similar morphology), but one I recently bumped into and found particularly curious. Why? Because it's morphology seems to contradict itself. Described as a Polyptychodon interuptus (no longer considered a valid genus; Madzia [2016]) from the Late Jurassic Volga Beds (?) of Stary Oskol, the tooth appears to have enamel folds consistent with what one might expect from an ophthalmosaurid ichthyosaur, such as Platypterygius sp.. The root, however, is smooth and round, with a hollow base, which, unlike the rectangular and "fibrous" roots more typical of ophthalmosaurid ichthyosaurs, is more indicative of pliosaur. Here are some pictures of the tooth. Unfortunately, as it was sold off by auction back in 2017, there's no chance of getting any better quality photographs: I know the seller is quite familiar with pliosaur teeth, so would be surprised if they identified the tooth wrongly. The ornamentation on the tooth, however, bugs me as not matching what I would expect for pliosaur, especially a brachauchenine species. Below are a schematics illustrating various tooth crown ornamentations amongst marine reptiles (figure 2 from McCurry et al. [2019]) and some examples of British brachauchenine pliosaur teeth (figures 3, 4, 5 and 6 from Madzia [2016]) for comparison. Tooth ornamentation in marine reptiles: A. Deinosuchus rugosus; B. Spinosaurus; C. Ichthyosaurus; D. Pliosauridae indet.; E. Globidens alabamensis; F. Hydrurga leptonyx; G. Mammalodontidae indet. Here's the only confirmed Stary Oskol pliosaur tooth I've been able to find as a reference for how the above translates to that location (source): And, finally, for completeness, some Stary Oskol platypterygiine ichthyosaur teeth: My questions to you are: Does this look like an ichthyosaur or pliosaur tooth to you, and why? I've heard, by word of mouth (i.e., got from a source that's not academic), that certain late ophthalmosaurid species developed root tooth roots. Can anybody confirm or deny this, if possible with academic reference? Thanks for your help! @RuMert @Anomotodon @paulgdls @PointyKnight @Mike from North Queensland @-Andy-- 13 replies
-
- 1
-
- ichthyosaur
- marine reptiles
- (and 6 more)