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RE: Burpee Conference



Indeed the Hell Creek has been picked over for over a hundred years, but
it has only been in the last decade that T rex has been found in
abundance, almost becoming "oreodonts of the Cretaceous" ;-)  Most work
has been done in the upper-most Hell Creek around the Ft Peck Reservoir.
The middle and lower parts have many secrets that are only now being
revealed: The first Leptoceratops skull (now in press), and two partial
skeletons of a giant oviraptorid (new genus). It may be significant that
the type Nanotyrannus and the Burpee specimen come from the southern
portions of the Hell Creek (Carter County), which has a very different
lithofacies than up around Ft. Peck Reservoir. Carter County samples
more of the lower and middle Hell Creek.

Ken

Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology/Chief Preparator
Department of Earth Sciences
Denver Museum of Nature & Science
2001 Colorado Blvd.
Denver, CO 80205
 
Phone: 303-370-6392
Fax: 303-331-6492
************************************************************
for PDFs of some of my publications, as well as information of the Cedar
Mountain Project: 
https://scientists.dmns.org/sites/kencarpenter/default.aspx

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf
Of Phil Bigelow
Sent: Tuesday, September 20, 2005 9:12 AM
To: dinosaur@usc.edu
Subject: Re: Burpee Conference



On Tue, 20 Sep 2005 12:14:20 -0700 (PDT) Guy Leahy
<xrciseguy@prodigy.net> writes:
> Before the conference, I was leaning
> towards the "Nanotyrannus is a T. rex" hypothesis, but
> after the conference I have lept back on the fence as
> to whether Nanotyrannus is a juvenile T. rex or a
> juvenile of something else.

The big question is, if "Nanotyrannus" is a juvenile of some other
taxon,
then why haven't we discovered any of its adults in the Hell Creek
Formation?  The H.C. Fm is one of the most "combed-over" formations in
the U.S. (as well as the world).  It has been picked over for over a
hundred years.

In their 1988 _Hunteria_ paper on "Nanotyrannus", Currie, Williams and
Bakker discussed whether "Nano"'s cranial sutures were, or were not,
fused.  IIRC, they claimed that the sutures were fused.  Since then, I
have read comments that suggest that there is still some question about
the degree of element fusion on the holotype's skull.  Any update
regarding this question?

The null hypothesis is that "Nano" parents occupied the same geographic
range as did their kids.  Migration or separation of the kids from the
adults are also viable ideas, but those scenarios involve more
complexity
and therefore they are not as parsimonious ideas as are mingled adult
and
juvenile populations.

Except for their shed teeth, which are more common that thought, the
skeletons of "Nanos" are rarer than pachycephalosaur skeletons (and
pachys are quite rare).

Nano nano,

<pb>
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