Re: Triceratops sprawl

[Robert.J.Meyerson@uwrf.edu (Rob Meyerson)]

>> Even if the ribs were misarticulated, this wouldn't necessarily prove=
 that=20
>the animal had an upright posture. =20
>
>     If the ribs are oriented correctly, the scapula is oriented=20
>correctly relative to the ribs, and the humerus is oriented correctly=20
>relative to the scapula, it certainly would.  The non-sprwaling model is=20
>consistent with the fossil material, our understanding of how vertebrate=20
>and dinosaur skeletons articulate, and the trackway evidence.=20

Again, I am not convinced that this evidence (which is mostly circumstancial
anyway) really shuts the door on sprawling posture.  If you look at the data
another way, sprawling posture becomes possible.

The crux of the problem may be that the upright hind limb/sprawling forelimb
mount appears to be so wierd, that its easy to doubt the accuracy of this=
 mounting style.  Besides, it could be argued that the ceratopians simply=
 found a unique solution to the problem of going from a bipedal animal to a=
 quadrepedal one; especially when one considers that the environment in=
 which they lived was extremely treacherous (how better to manuver in the=
 ancient Gobi dune fields than to adapt a dune-busting form).

Rob

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