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RE: dinosaur beaks and ora speeds




Michael Lovejoy wrote:

> Tim Williams wrote "IMHO, _Alioramus_, Carcharodontosaurus_, > _Majungatholus_ and other non-maniraptorans, by contrast, were > not "beaked", but nevertheless had a cornified zone expressed on > the dorsal rostrum (perhaps continuous with any pre- or postorbital > ornamentation)"

So, we're talking about a possible horny covering across the nasals, but nothing on the premax.?

The horny covering did not extend to the ventral margin of the premaxilla. When the horny covering provides the cutting edge to all of or part of (i.e. the front) the jaws, then it qualifies as a beak. In a previous post I was a little sloppy in my terminology; _Carcharodontosaurus_ did not have a beak, but it probably had a cornified region atop the snout. As Darren alluded to, the ridges and horns that adorned the skulls of many theropods were possibly encased in a horny sheath.




Tim

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