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RE: Velociraptor profiles



 
Jerzy Dyczkowski wrote:

> There are several ways to check if Velociraptor was fighting with live
> one or grasping the dead Protoceratops. Unfortunately, all require 
> access to primary fossil.

I suspect that establishing all your pre-conditions to be in the negative
would not settle the issue...

> - examintion of fossil surrounding - is it really likely that these
> missing Protoceratops bones were destroyed? Gobi fossils are famous of
> good preservation, including vertical Protoceratops trying to dig itself
> out the sand.

Mongolian specimens are famous for comprising well-preserved, articulated
skeletons; but very few are actually complete (i.e. with every individual
bone intact).  These specimens are often discovered because a particular
bone is sticking out from the rock - meaning that the skeleton has already
been exposed to erosion.

> - claw marks on Protoceratops skull and ribs. If Velociraptor claw was
> killing weapon, and Velociraptor was fighting it's claws should leave
>  marks on bone. Less likely, if it was grasping the carcass.

I don't think this is necessarily true.  The purpose of the "killer-claw"
may have been to subdue the prey by (a) slicing across the neck to open up
the jugular and (b) slashing through the torso and weakening the prey victim
by blood loss.  Neither requires that the "killer-claw" (or the hand claws,
which may have also have raked across the torso) to come in contact with the
bone.  In fact, there are good reasons why _Velociraptor_ may have wanted to
avoid this.  Dragging the claws across the rib cage (like running a stick
across a picket fence) may have broken or blunted the claws.

> - Velociraptor tooth marks commonly found on other Protoceratops
> fossils.

Again, unless the _Velociraptor_ gnawed the bones, this particular predator
may have stuck with the easy-to-get-to muscles and viscera to sate its
appetite.  Other predators (and, of course, scavengers) may have 
picked the bones clean.

And, as John Conway mentioned, tooth marks on fossil bones only prove that
the predator fed upon the flesh attached to the bones - not whether the prey
was alive or dead when the predator first came across the prey.

> And this only leaves nasty question: if Velociraptors were skillfull
> pack predators, why would one allow itself to be killed by about equal-
> sized herbivore? 

Pack-hunting has been proposed for _Deinonychus_, on account of the
association of several individuals with _Tenontosaurus_ - but I don't recall
this behavior being explicitly proposed for _Velociraptor_.  As to why a
_Velociraptor_ allowed itself to be disabled by a _Protoceratops_ - sh*t
happens, I suppose.  Perhaps the _Velociraptor_ was caught off guard by a
sandstorm.

> I suppose that nobody will ever check it, especially as it would spoil
> the nice tale to sell for the media (and other paleo-lovers).

In this era of headline-grabbing, sensationalist reporting of
paleontological research, your cynicism is warranted.  However, in the case
of the "Fighting Dinosaurs", this particular tale does have a solid
scientific foundation.  A scenario that casts _Velociraptor_ as the
aggressor and _Protoceratops_ as the victim is the most parsimonious
interpretation of the available evidence.  The fact that it's also the most
exciting interpretation should not count against it.



Tim


------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163