Re: Ceratopsian gait (was Re: Oviraptor)

[Jeffrey Martz <martz@holly.ColoState.EDU>]

> What of the recent (1997 or 1996, can't remember which) studies on
> ceratopsian forelimbs that seem to indicate that a somewhat sprawling
> gait is more likely? 

      The _Torosaurus_ mount that was mentioned in 
"Functional Morphology in Vertebrate Paleontology" may have gotten at
least some of the sprawl from the orinetation of the ribs.  Greg Paul has
mentioned in the past that rib orientation palys a big part in how badly
the animal sprawls; if the ribs swing out to far, the scapula, and
therefore the glenoid, are also twisted around so that the entire forelimb
would sprawl.  Peter Dodson in his book on "Horned Dinosaurs" suggests
that playing with the ribs would do little to alleviate the sprawl, citing
Kenneth Carpenters mount of the _Chasmosaurus_ in Philedelphia as
evidence.  However, Ken himself agrees somehwat with Greg Paul, citing the
same mount as evidence.  The _Torosaurus_ mount apparantly had the ribs
sticking out more or less perpendicular to the vetrebral coulmn.  The ribs
in both modern anaimals and articulated dinosaur skeletons has the ribs
orineted more backward, so they can act as a bellows.  Check out the
Quicktimes of Ken's _Chasmosaurus_ at:

http://www.acnatsci.org/dinosaurs/movies.html

     Mostly side views, unfortunately.  The forelimbs may not look quite
like a rhino, but they aren't sprawled as in badly as the _Torosaurus_
mount.         
   
LN Jeff
O-