Delicious Triceratops Goodness

[Michael Erickson <tehdinomahn@live.com>]

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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