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Re: Oviraptorids as Parrots?



Jura (pristichampsus@yahoo.com) wrote:

<Extant alligatorids do maintain some rounded rear teeth. Low and behold, these
are also the only extant crocodylians to show a dietary preference for
turtles.>

  How do you mean, a dietary preference? A preclusion to eat, or a greater
tendency to have a diet consisting of turtles than other animals? If so, what
statistical studies show this?

<Morphologically, turtle eaters tend to show rounded, separated and deeply
rooted teeth. Whereas molluscivores (the other major shell crushers) show
tightly spaced, flat and shallow rooted teeth.>

  Broad snouted crocodylids, contrary to the above quotes passages, manage to
eat turtles despite having more or less isodont conical dentition. Both
*Crocodilus porosus* and *C. moreletti* are noted for consuming turtles, and it
has been suggested that this is true of the American croc or caiman (*C.
acutus*), as well as the Nile croc (*C. niloticus*). While most crocodylids
tend to have slender, gharial-style snout morphology, this does not appear to
stop the bigger animals from taking prey they can crush and consume.

<Along with _Deinosuchus_, there were a few more crocodyliformes that are
believed to have been...er, chelonivorous. _Phosphatosaurus, Brachychampsa_ and
_Albertochampsa_ also show turtle eating dentition.>

  They have been, in fact, described as durophagous, and the same is true of
various paraphyletic species of *Allognathosuchus*, as well (Brochu, 2005).

<Schwimmer also mentions a few more pieces evidence, including the close
association of various chelonian species with _Deinosuchus_ and (perhaps most
compelling of all) the presence of fossilized turtle shells showing various
bite marks and puncture wounds. Many of these wounds fit a _Deinosuchus_ tooth
remarkably well.>

  Have you fitted the teeth to show? Might make a good paper. However, most
Cretaceous through Neogene crocs appear to have been associated with testudines
anyway, so this association of one (even large) testudine with a large
crocodyliform seems associative more than it seems evidenciary of diet.

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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