RE: Young rex, triceratops...

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

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

> Casts of the little skull can be seen between the _Styracosaurus_ and the
> adult _Triceratops_ skull casts in the "Display or Defense" ceratopsian wall
> in the American Museum of Natural History's traveling show, "Dinosaurs:
> Ancient Fossils, New Discoveries."

And damn cute, I have to add...

> Mark Goodwin expected his paper on the littlest trike to be published soon
> in the Journal of Vertebrate Paleontology.  WFTFP.   =%^P

Excellent!!

Although Horner didn't state it as such, I noted at the talk that several of 
the features (especially concerning development of the
nasal horn and orientation of the postorbital horns) that distinguished 
subadult from adult _Triceratops_ are ALSO traits used to
distinguish _Diceratops_ from _Triceratops_. So regardless of whether 
_Diceratops_ is its own genus (or species of _Triceratops_) or
not, the type was likely not fully grown.

> I don't know how many juvenile _Tyrannosaurus rex_ specimens are known, but
> some excellent _Nanotyrannus_ (considered to be young _T. rex_ by many)
> specimens have come to light, including the Cleveland Museum of Natural
> History specimen, and "Jane," who resides at the Burpee Museum of Natural
> History in Rockford, Illinois.  See    <http://www.visitjane.com/temp.cfm>

Indeed, I believe that Horner is among the "_Nano._ as baby rex" crowd (as am 
I, for the time being).

                Thomas R. Holtz, Jr.
        Senior Lecturer, Vertebrate Paleontology
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
        Mailing Address:
                Building 237, Room 1117
                College Park, MD  20742

http://www.geol.umd.edu/~tholtz/
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