Re: Re: Erlic/kosaurus

[Thomas_R_HOLTZ@umail.umd.edu (th81)]

George Olshevsky (first quoting Jonathan Wagner) writes:

>>In this case, it seems that postcranial features are pushing us to
>>the conclusion that segnosaurs are derived coelurosaurian theropods.
>
>Which postcranial characters are these? Pneumatization of the axial
>skeleton, which runs rampant through Theropoda and even Prosauropoda
>and Sauropoda?  Semilunate carpal, which I have yet to see in any
>segnosaurian specimen, but which everybody says is there (like the
>emperor's new clothes)?

Try checking out Barsbold's Carnivorous Dinosaurs of Mongolia opus, in
the carpal figures, for one.  There was also a paper by Barsbold (&
Perle?) on therizinosaur limb elements which has many of the same
illos.

>Don't forget that Huene once thought prosauropods were closely
>related to coelurosaurians.  The coelurosaurian features you may see
>in segnosaurs could be their coelurosaur-like prosauropod characters
>in various derived states.

Or they could be coelurosaurian features with some prosauropod
convergences.  Either is possible.  To evaluate between the
possibilities, we must use some technique for comparing the
alternative working hypotheses.

Anyone want to actually DO a cladistic analysis with 'prosauropods',
therizinosaurs, and various theropods?  Might be nice for a class
project.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661

"There are some who call me...  Tim."