Re: Torosaurus NOT Triceratops--?

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

On Wed, February 29, 2012 8:43 pm, Paul P wrote:
> Interesting paper, but inconsistencies in the characters
> that supposedly indicate maturity are a problem (and
> not just for this paper). It seems to me that a young
> juvenile specimen will be needed if this issue is ever
> to be resolved. It's not enough to have big skulls that
> might have a few unfused sutures or some lingering
> striated texture.

Agreed. I raised the issue at the original Scanella Bristol talk that we
should check the postcrania of large individuals of both morphs for EFS,
and this has either not been done or not been published.

Furthermore, this idea that maximum body length of individuals is somehow
taxonomically significant really has to go. We know that many taxa have
variable maximum body size of individuals, so having some subadults bigger
than adult individuals isn't rare.

> One thing i notice is:  the authors pretty much ignore
> AMNH 5116 which is a good candidate for an intermediate
> if ever there was one.
>
Indeed. In fact, I would not at all be surprised if--should Torosaurus and
Triceratops turn out to be distinct taxa--that AMNH 5116 is a subadult
Torosaurus, not a Triceratops.
>

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
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