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WHAT are segnosaurs?




Mickey,
Thank you for testing a null hypothesis. But I suspect that similarities between prosauropods and therizinosaurs are going to turn out to be plesiomorphic, and therefore rather tenuous and unconvincing.
What I envision is therizinosaurs as stem tetanurans (perhaps small unknown primitive forms being stem neotheropods), and eventually grading into primitive coelurosaurs and even primitive bullatosaurs (ornithomimids and troodontids).
Therefore instead of comparing therizinosaurs to prosauropods, it might be more interesting to compare them to Guaibasuarids, Coelophysids, Sinraptorids, and/or basal coelurosaurs such as Ornitholestes. I suspect that Beipaiosaurus may be a rather advanced therizinosaurian (whether the latter is a paraphyletic group or polyphyletic).
If therizinosaurs (as now envisioned) are actually polyphyletic or even highly paraphyletic, splitting them into a number of separate OTUs may become necessary (but then the fragmentary nature of most forms would become extremely problematic). But I would especially like to see some concerted attempts to compare various therizinosaurians particularly with sinraptors and primitive coelurosaurs (as opposed to prosauropods which are probably more primitive).
Just a suggestion,
Ken Kinman
*******************************************************
From: "Mickey Mortimer" <Mickey_Mortimer11@msn.com>
Reply-To: Mickey_Mortimer11@msn.com
To: <dinosaur@usc.edu>
Subject: Re: maxillary fenestration & WHAT are "segnosaurs"?
Date: Thu, 28 Jun 2001 21:02:50 -0700

Tracy Ford wrote-

> 2) I have no problem with the jaw being a therizinosaurid, its the rest of
> the skeleton that I have a problem with. The jaw is to small to go with
the
> skeleton (as I've said numerous times on the list).


I'm preparing a big list of theropod characters present in segnosaurs and
going to put segnosaurs in a prosauropod matrix, but until then....
As I wrote before-
Strange that the skull would be too small when the authors state the dentary
is 65% of femoral length, which they point out is larger than other
segnosaurs.
How can the skull be too small in this case?


Mickey Mortimer
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