Quite some time ago, I fell in line with the authors in reconstructing the weird Atopodentatus unicus with a particularly Lovecraftian face. I won’t apologize for this reconstruction, I followed the implied anatomy the authors presented and couldn’t distinguish what, at the time, looked like a reasonable reconstruction but was not, in fact, correct.
I present now an improved reconstruction. (The feet aren’t even backwards as they’d been in my drawing, above…)
Almost immediately after publication, new information was shared throwing doubt onto the reconstruction, and this was published two years later by some of the same authors revealing that the original downturned L-shaped face was, in fact, a sideways splayed T-shaped “hammerhead”.
This actually makes more sense, given implications the animal might be a bottom-feeding dredger or adapted for scraping algae off stones. The peculiar split face and downturned snout might interfere with obtaining food, in that suction through the conventional mouth might cause outflow back through the split; whereas rather than suck through the split, the mouth need only be opened.
Dorsal and caudal vertebrae each have an anterior and posterior process leaving a small rounded or triangular tip, a feature I note might provide a deep fleshy extension of the spine above the interspinous muscles that define the curve of the back. These create a sense of “notches” and one might be tempted to place something like osteoderms into these slots, but despite there being three distinct specimens none such are apparent.
Rather than speculate on this, the reconstruction is left “as is.” (I’ve also omitted reconstructing sternal cartilage and ribs.) Tail fins, extra dorsal frills, etc. have also been omitted; this being a very “bare” reconstruction as things go. I have given Atopodentatus unicus webbing between its digits and a sorta half-cheek to support suction feeding.
So there you have it.
Cheng L., Chen X.-h., Shang Q.-h. & Wu X.-c. 2014. A new marine reptile from the Triassic of China, with a highly specialized feeding adaptation. Naturwissenschaften 101:251-259.
Li C., Rieppel, O., Cheng L. & Fraser, N. C. 2016. The earliest herbivorous marine reptile and its remarkable jaw apparatus. Science Advances 2(5):e1501659