RE: dinosaur beaks and ora speeds

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> The skull of _Alioramus_ shows good evidence for a
> beak, at least
> according to the criteria used to judge whether a rhampotheca was
> present or
> not (see Darren's post).  The same evidence can be marshaled in
> favor of a
> beaked _Carcharodontosaurus_ as well.
>
Hmmm...

Well, I would add that in living beaked reptiles (turtles, birds), as well
as extinct forms generally accepted as beaked (ornithomimosaurs, for
instance) there is a relatively sharp edge between the lateral and ventral
surfaces of the maxillae.  In contrast, in _Alioramus_ and _Carch._ there is
a curved surface grading the lateral into the ventral surface.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796