RE: Tyrannosaurus "Scavenger vs. Predator" debate - Some questions for Dr. Jack Horner:

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On
> Behalf Of Vladimír Socha

> < > Therefore, it is tantalizing to speculate that perhaps,
> < > like their distant Southern Continental cousins, T-Rex
> < > may also have solved this problem by cooperating and
> < > hunting in packs, or prides, where the animals' role in
> < > the hunt would be dictated by its age and size.

> Yes, this idea is supported by the finds of "Sue" with two other
> individuals (probably even bringing her food since she had broken
> leg for some time) and another  find of 5 specimens in one place
> during 2000 Hell Creek expedition. Vlad

Unfortunately, despite earlier claims to the contrary, there is no evidence
"Sue" ever broke her leg.  CAT scans show that the pathological fibula was
never broken: instead, the growth was probably a reaction to infections.
(So "Sue" wouldn't have been in the best of moods, but wouldn't necessarily
have been immobile or even too dramatically reduced in locomotory
performance).

Also,  we have yet to get the details of the taphonomy of the new Hell Creek
specimens: we don't know  yet if the 5 specimens "found at the same place"
were really closely associated, or on different stratigraphic levels, or
whatever.

That being said, Barnum Brown's Albertosaurus site, and the "Sue" and Jordan
T. rex sites, do suggest occassional multi-age class gatherings of
tyrannosaurids.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
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