Dromaeo pubes & Oviraptor sterna

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

At 07:26 PM 2/24/99 EST, EctoDino wrote:
>Thank you for your reply, I enjoyed it.
>       I have Dingus & Rowe's "The Mistaken Extinction." In this book, they 
> show
>Deinonychus with the outdated vertical pubis AND with a hypopubic cup (no
>boot) that is repeated in Rowe's CD-ROM: The Age of Dinosaurs.

Actually, they don't show a hypopubic cup for _Deinonychus_ (or rather, they
don't show a view where one could tell, because the morphology of this "cup"
or "spoon" is only clear in posterior view).  The pubic boot for
_Deinonychus_ as shown is based on real specimens.

(Something that Ruben et al. haven't seemed to have commented on is the
great diversity of pubic boot size and shapes within Theropoda:
_Herrerasaurus_ is different _Coelophysis_ is different from _Carnotaurus_
is different from _Torvosaurus_ is different from _Sinraptor_ is different
from _Allosaurus_ is different from _Gasosaurus_ is different from
_Coelurus_ is different from ornithomimids are different from tyrannosaurids
are different from oviraptorids, etc., etc.  To then say that the particular
morphology as they see it in _Archaeopteryx_ could not (or is unlikely to)
have evolved from within coelurosaurian theropods seems a bit odd).

Oh, and for those who have access to Rowe et al.'s Age of Dinosaurs CD-Rom
version 3.0, there is an excellent tutorial on systematics and reading
cladograms and what not, in case you are interested.

And Jaime A. Headden wrote
><If we used the breastplate argument, than spinosaurids and
>_Sinraptor_ (both of which have fused, keeled sterna) were closer to
>modern birds than Archie, dromaeosaurids, oviraptorids, etc.>
>
>  Except that oviraptorids and dromaeosaurids are known to possess
>fully ossified sterna with both possessing a crista (or keel), as seen
>in specimens GI 100/30 and 100/25 (*Ingenia* and *Velociraptor*,
>respectively). (Barsbold, 1983.)
>
>  To quote from that article:
>
>  "[Refering to the Oviraptoridae] A medial projection of the cranial
>region of the cleft is sharp and isolated in relief from the adjacant
>parts of the sterna." (Barsbold, 1983: 34.)

Quite so.  What I should have pointed out was that _Sinraptor_ and
_Baryonyx_ were more like modern birds than some *specimens* of dromaeos,
oviraptorids, etc.: in _Sinraptor_ and _Baryonyx_ the sterna are fully fused
to each other into a single block with a keel, whereas some maniraptoran
specimens (i.e., the dromaeosaurid specimen IGM 100/985 in the Norell and
Makovicky paper) the left and right plates have not fused along the midline.

As a follow up to a post I just sent (in reply to James Norton), I mentioned
that Am. Museum Novitates could be obtained over their website.  I forgot to
mention it, and will do so here:
http://nimidi.amnh.org

Back issues of Novitates and Bulletins of the American Museum of Natural
History published during the last five years are available through this site.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:tholtz@geol.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661