Re: [proto]Ceratopsian gait

["Matt D. Celeskey" <mceleskey@cabq.gov>]

dannj@alphalink.com.au (Dann Pigdon) wrote:

>>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?...Is this not a popular view then?
Of course this does not relate to protoceratops itself, so for all
I know Tracy's statement may well be true, but any chance to stir
the coals...  :)

More directly related are the posture and locomotion studies of _Protoceratops_
done by (if memory serves) Tereschenko...his contention is that the forelimbs
were held erect and the hindlimbs were sprawled slightly - check the photos of
the Field Museum mount in Glut's Dinosaurs: the Encyclopedia, they seem to show
the hindlimbs sprawled about the same amount. This is based on his work
reconstructing the spinal column, showing that the back was held nearly
horizontal around the shoulders and sloped down at the hip.

His studies on locomotion suggest that _Protoceratops_ would have been able to
begin a sprint bipedally, falling into a quadrupedal trot once the weight of its
head overcame the inital momentum. He also mentioned that the vertebral column
was much more flexible in the lateral plane than the vertical one, which would
have made galloping (suggested by Bakker) unlikely.

I haven't heard much about this work, and was wondering if anyone with more
knowledge of locomotor studies could comment on the reliability of his methods
and conclusions. I would think that this would have a direct bearing on the
ceratopsid forelimb controversy, unless quadrupedality evolved twice within the
Neoceratopsia. I'd be happy to look up the refs for anyone who's interested...

Matt.
mceleskey@cabq.gov
http://www.io.com/~mwalk/hmnh/hmnhmain.html