Re: Postosuchus stance

[William_Parker@nps.gov]

No specific tracks have been referred to Postosuchus, but Chirotherium has
been attributed to a "rauisuchid" trackmaker.  Interestingly, Chirotherium
is from a plantigrade, quadrupedal animal and there is much debate over
whether Postosuchus was a biped or quadruped.  Evidence against
quadrupedalism in Postosuchus are the very reduced forearm and tiny manus;
however, the Chirotherium track maker also has a very small manus.

A cool reconstruction is here:

http://en.wikipedia.org/wiki/File:Chirotherium.jpg

I also addressed this briefly here:

http://chinleana.blogspot.com/2009/01/was-postosuchus-bipedal-or-quadrupedal.html

************************************************************************
Bill Parker
Vertebrate Paleontologist
Division of Resource Management
Petrified Forest National Park
P.O. Box 2217
1 Park Road
Petrified Forest, AZ 86028
(928) 524-6228 x262


                                                                           
             David Krentz                                                  
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   What trackways have been attributed to Postosuchus?  Do they show
full plantigrade feet, ( is a crurotarstian considered
plantigrade)  ?  Do they show a wide stance with in the front arms or
are they more indicative of a more erect posture?
Does the manus rotate outwards?

   This is truly a really cool creature!

D