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RE: Delicious Triceratops Goodness



Cool stuff. I have never liked the sprawling forelimbs, it just looks wrong
for starters.

Does this mean that all ceratopsian CGI will have to be redone?

Does it also extend to ornithopods?  I have often wondered about the ability
to walk bipedal and quadrapedal and the orientation of the forelimb in both
modes.  

-----Original Message-----
From: Michael Erickson [mailto:tehdinomahn@live.com] 
Sent: 01 January 2010 05:21
To: Dino List
Subject: Delicious Triceratops Goodness


Just in case there are ceratopsian buffs on this list who haven't noticed,
this paper is now out:


Fujiwara, Shin-Ichi. A Reevaluation of the Manus Structure in Triceratops
(Ceratopsia: Ceratopsidae). Journal of Vertebrate Paleontology 2009 29 (4),
1136-1147.
 
ABSTRACT: A Triceratops, NSM PV 20379, excavated from the Upper Cretaceous
Hell Creek Formation, Bowman County, North Dakota, USA, confirms the
articulation of the right forearm. Detailed study of the forelimb anatomy
presented here indicates the manus is in a semi-supinated orientation. This
reconstruction is based upon the following morphology: the row of the
metacarpals was arranged in an 'L'-shape in proximal view, as is the distal
articular surface of the forearm is in articulation; the second digit is
directed parallel to the rotational plane of the elbow joint, reinforced by
neighboring digits I and III, and these three inner digits are articulated
with the broad articular surface of the radius. Arrangement and directions
of robust inner digits seem to be suitably arranged for a powerful stroke
exerted by the elbow joint extension. Cerapods, including ceratopsians and
ornithopods, share following morphology of the manus: long and robust
metacarpals II and III, ungual phalanges on digits I to III, reduced digits
IV and V, and a divergent metacarpal V. A laterally oriented manus with
reduced outer digits is present in the basal bipedal group of the Cerapoda.
Although reversal to a quadrupedal stance and a evolution to a large, heavy
body occurred independently in many lineages of Cerapoda, the basic features
of the manus were retained throughout Neoceratopsia.

This is an absolutely awesome paper. It confirms that *Triceratops* had
parasagittal rather than sprawling forelimbs; however, the new
reconstruction has little else in common with previous reconstructions. The
manus is a whole lot weirder than ever pictured before. Only the inner three
fingers bear the bulk of the animal's weight and they (the manus) are
incapable of actual pronation and thus the radius and ulna are uncrossed -
among many, many other things.
 
Seriously cool stuff.
 
P. S. I can send a copy of the paper to anyone interested, and thus return a
fragment of the many paper-giving favors done for me by other list members
:)
 
~ Michael                                         
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