RE: FEATHERS FOR T-REX?

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Jaime A. Headden
>
>   Ornithomimosauria has, as far as I can tell, been defined as
> {*Ornithomimus* > *Troodon*}, by Holtz, in accordance with the
> Bullatosauria hypothesis. This gives the taxon a lesser subjective use
> than Arctometatarsalia in some hypotheses. Problematically, Sereno defined
> (1999) Ornithomimidae {*Ornithomimus* + *Pelecanimimus*}, ignoring
> Ornithomimosauria, and including Alvarezsauridae in his Ornithomimoidea
> {*Ornithomimus* + *Mononykus*}.

To add a third definition, Padian, Hutchinson & Holtz (1999) used the
version "all descendants of the most recent common ancestor of
_Ornithomimus_ and _Pelecanimimus_", making a node-based Ornithomimosauria
within the stem-based Arctometatarsalia.

                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