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RE: T. bataar (was RE: It's HERE!!!)



> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Mickey_Mortimer
>
> > I think you may want to have a second thought about that laugh, though,
> > without considering the aspects of intraspecific variability
> and questions
> > about accuracy of illustrations...  Indeed, there may be a lot fewer
> > ornithomimosaur species and genera currently represented in collections
> than
> > represented on websites and published taxon lists.
>
> Well, unless you have unpublished information up your sleeve..... I can
> picture it now-
> Holtz and Barsbold, 2001. A reanalysis of ornithomimids (Dinosauria:
> Theropoda) of the Cretaceous of Laurasia. JVP 21(1) 105-142.

Actually, it's not me whose doing it: its someone else who used to post to
this list... :-)

> Well, as I was saying, if you have unpublished evidence I'll have
> to eat my
> words in the future, but for now Anserimimus and Gallimimus seem extremely
> dissimilar as far as ornithomimids go.

Other than ungual form, how do you get these as being "extremely
dissimilar"?  More on _Anseri._ unguals below.

>  Garudimimus as a junior synonym of
> Archaeornithomimus I can see.  Dromiceiomimus samueli being
> synonymized with
> D. brevitertius is plausible.  Ornithomimus edmontonensis and O.
> velox could
> easily be the same, as could Coelosaurus antiquus.

Not to preempt anyone's work, but go back sometime and see exactly what
features are used to distinguish the North American forms from each other,
and consider how strongly these types of characters are regarded now.

> Gallimimus "mongoliensis" proving to be G. bullatus is possible.

More to the point, demonstrating that this is anything other than a new
specimen of _Gallimimus bullatus_ is something that hasn't been done yet!

> Anything
> could happen
> to Timimus, "Orcomimus", "Sanchusaurus", Ornithomimus? tenuis, O?
> sedens, O?
> affinis or Archaeornithomimus? bissektensis and I wouldn't be surprised.
> But a few taxa seem as stable as anything else in paleontology, including
> Pelecanimimus, Deinocheirus and Anserimimus.  Then again, who knows what
> tomorrow will bring....

_Pel._ and _Deino._ I definitely buy; however, there is little described in
_Anserimimus_ so far that is distinctive from the _Gallimimus_-North
American ornithomimid complex.  The manual unguals of _Anserimimus_ (its
main diatgonstic feature) do not seem to be dramatically different from
those of some of the North American forms (and I suspect that _Anseri._ is
destined for junior synonymy, although not necessarily with _Gallimimus_).

Now the task hasn't been done yet, so most of these names are still
considered valid.  However, even more than tyrannosaurines or ankylosaurids,
the derived ornithomimids are 'much of a muchness', and very likely are
oversplit at present.

                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