RE: Daspletosaurus temporal/stratigraphic range

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Tim Donovan
>
> Is Daspletosaurus known exclusively from Campanian units, or is there
> evidence of it in the Horseshoe Canyon or equivalents?

At present, Campanian only.  See Carr and Williamson (2000, NM Mus. Nat.
Hist. & Sci. Bulletin 17: 113-145) for a review of the southern part of the
range.  Some consider CMN 11315 from the Horseshoe Canyon a posssible
Daspletosaurus, but I have seen no evidence in that specimen that it is
anything other than Albertosaurus.

> What is
> the age of a
> daspletosaur reported to resemble Tyrannosaurus more than others?

If by this you mean the Two Medicine specimen briefly described by Horner et
al. (which, in fact, may simply be Daspletosaurus torosus, or it could be a
new species of D.), it is late Campanian.

> Is there
> any possibility that TMM 41436-1 represents a Daspletosaurus?

Possible, yes.  Any evidence pointing to it being a Daspletosaurus rather
than a juvie T. rex, no.

                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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