RE: TYRANNOSAUROID SEMILUNATE etc

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> darren.naish@port.ac.uk
>
> Delayed response as always, but for what it's worth..
>
> RE: semilunate carpal of _Coelurus_ and tyrannosauroids, the former
> does have one and Nick Longrich provided good drawings of it in his
> thesis. The news from this end is that _Eotyrannus_ has a near-
> identical semilunate to _Coelurus_ (I've been using Nick's drawings in
> my comparisons). If _Eotyrannus_ is a basal tyrannosauroid this is
> further support for the semilunate condition in primitive members of
> this group. Can go no further with this at this time so don't ask for
> more details.

The semilunate of tyrannosaurids, such as it is, resembles that of
_Coelurus_ in at least one specimen.  That specimen, NMC 11315 (a juvenile
from the Horseshoe Canyon, catalogued as _Daspletosaurus_ sp. but might well
be a young _Albertosaurus sarcophagus_) has the carpals in articulation.
The semilunate element is small (it does not fully cap either MCI or MCII),
but it does have a trochlear structure.

A really bad sketch (I have never claimed to be an artist!!!) will be seen
on Fig. 3 of my contribution to the Ostrom Symposium volume.

                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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