Protoceratops/Velociraptor

[Phillip Bigelow <n8010095@henson.cc.wwu.edu>]

Mike wrote:-

> The famous Velociraptor and Protoceratops found in a deadly 
embrace,
> with P's jaws clamped around V's forearm and V's clawed foot 
where P's
> belly would have been, supports this.  V didn't stick its arm into P's
> mouth on purpose -- P must have intentionally caught V's arm, 
implying
> it could have been a `standard' defense behaviour.
> 

Have the Mongolians been able to prepare around the mouth/arm region enough
to get a good look at the Velociraptor's arm bones?  Are they broken?
Knowing the cross-sectional dimmensions of the broken bones, size of
medulary cavity, etc., a bio-physicist could calculate the biting force
necessary to break those bone(s).  A relatively easy calculation, actually.
Paleo-anthropologists/paleontologists like Dr. Pat Shipman could supply more
information on the calculations, but it is pretty straight-forward stuff.
Was Protoceratops biting with a "holding" or "restraining" force, or was the
little beast trying to deliver a killing bite?  If the bones aren't broken,
it may indicate a restraining-action on the part of Protoceratops (or
weaker-than-expected jaw muscles). 
  It is relatively easy to distinguish between paleo-fractures, and
fossils that have been fractured through lithostatic loading/unloading.
 Paleo-fractures (often called "green-breaks") have curved breakage
surfaces.  The curved nature of the break is reflective of the high proportion
of interlayered bone collagen in fresh bones. 
 Fractures that occurred after fossilization (from various geological
processes) have more angular fracture surfaces in a myriad of angles and
orientations. The angles are determined by the crystallite morphology and
size of the apatite in the bones.  Bone collagen, although still present, is
much less abundant in fossil bones.