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Re: Mongolian dinosaur inspires religion in grad student



At 16:01 1/10/96 -0600, Jonathan Wagner wrote:

>        I am currently unclear on exactly how the systematics of the
>ornithomims works.  I know that there is a semi-ordinal taxon
>Ornithomimisauria, which sounds more than a tiny bit excessive to me (GSP
>says they're all in three genera, just to illustrate the opposite trend...).
>Since I have never heard a cladistic definition of that taxon, I hoped there
>wasn't one, and used it for the as-yet unnammed clade defined by
>Tyrannosauroidea (here again, I doubt a taxon larger than a super-family is
>necessary to adequitely describe this group) plus Ornithomoidea.  I disagree
>with Holtz (pers. com.), this taxon needs a name.  Of course, in the
>phylogeny I presented, this taxon recieves his name Bullatosauria.

Since I diagnose the clade Ornithomimosauria in the _Pelecanimimus_ paper,
and there is anode in the cladogram with this name, I think
Ornithomimosauria has been cladistically defined. That is, _Pelecanimimus_
and all taxa sharing a more recent ancestor with _Pelecanimimus_ than with
_Troodon_ (at least until my future work on the phylogeny of
Ornithomimosauria will be finished).

>        But of course!  The D-shaped premax teeth of Pelicanomimus are
>probably what keeps making the ornithomims come out as sister to the
>tyrannosaurs!

Have you included the other teeth in your analysis? By the way, the correct
spelling is both _Pelecanimimus_ and ornithomimids (Ornithomimidae).
 
>        I do realize that these traits are found in troodontids,
>ornithomims, and alvarezsaurs (IMHO these are oviraptorsaurs anyway...).  I
>was trying to make a case both for therizinosaurs as oviraptorsaurs, and as
>coelurosaurs, hence the confusion (possibly I worded the post too
>confusingly, I'll have to be more careful).  In the phylogeny I presented,
>these characters end up scattered all about the coelurosaurs, yet many of
>them do show up as synapomorphies of the Oviraptorsaria in their current
>position as sister to the Maniraptoriforms.

 Why do you consider that the alvarezsaurids are oviraptorids? I can't see it.

Bernardino P. Perez-Moreno                   Fax: 34-1-3978344
Unidad de Paleontologia                      E-mail: Nino@ccuam3.sdi.uam.es
Departamento de Biologia                     Phone: 34-1-3978139 
Facultad de Ciencias
Universidad Autonoma de Madrid
28049 - Madrid
SPAIN