Fighting dinos (was Re: Killing Claws)

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

Sam Girouard wrote:

>        Thomas Holtz commented on the "fighting specimen", GI 100/25:
>
>>Having seen slides of the fully prepared specimen, this shows some really
>>interesting aspects of interspecific combat.  In particular, one of the
>>hindfeet (the left, if I remember correctly) is placed with the sickle-claw
>>in the neck of the Protoceratops, not the belly as previously thought! 
>
>        I think is likely that this posistion was arrived at after the death
>of one or both animals.

Actually, this was exactly the question addressed by the talk (by D. Unwin &
colleagues) in which I saw the slides.  On positional, general taphonomic,
and sedimentological grounds, this position was achieved in their last
minutes of life, just prior to rapid burial.  There was some post-mortem
distubance of the Protoceratops' legs, but that's it.

>Why? If I was a Velociraptor, that would be the last
>place I would put my foot (or any other portion of my anatomy, for that
>matter!). The powerful beak of Protoceratops would have been its main
>defence, and I don't think a living Velociraptor would put its foot so very
>close to it. 

Actually, it is the arm (left forearm, I think) which was trapped in the
beak of the Protoceratops (no one said tackling an animal 3-4x your mass was
easy... :-).  The sickle claw, however, looks to be out of the reach of the
beak as positioned.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661

"To trace that life in its manifold changes through past ages to the present
is a ... difficult task, but one from which modern science does not shrink.
In this wide field, every earnest effort will meet with some degree of
success; every year will add new and important facts; and every generation
will bring to light some law, in accordance with which ancient life has been
changed into life as we see it around us to-day."
        --O.C. Marsh, Vice Presidential Address, AAAS, August 30, 1877