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RE: T rex symposium



> From: Ken.Carpenter@dmns.org [mailto:Ken.Carpenter@dmns.org]
>
> Thought Tom Holtz would post, so I'll force his hand.
> The conference was great, with many good talks (some with great
> animation showing working parts). Those of you who did not make it will
> be kicking yourselves in years to come. There was an impromptu
> discussion on Nanotyrannus vs T rex in collections on Saturday, but I'll
> leave that to Tom to address. It was great to have the collections open
> and to see casts or real speciemens of various T rex and related
> beasties.

I was having email issues earlier today (and today's just a half-day for me: 
got home after midnight...).

So, short form: Symposium was EXTREMELY good, in part because of a strong 
focus, in part because of the small size, and a lot
because of the ability to do interactions. Some of the folks doing computer 
simulations (e.g., Kent Stevens) were incorporating
suggestions from anatomists and the like right up to presentation time, for 
instance. And the aforementioned "Nano vs. Baby rex"
discussions among the specimens.

The facilities were nice, especially given that Hill City is a small town, and 
the presentations were in a highschool auditorium. It
was a good auditorium, though: nice seats, and nice projection equipment.

I left my materials at home, so I can't give a play-by-play of the whole event. 
But here are some highlights in terms of
presentations:

* Mary Schweitzer's showed ongoing work on that REALLY well-preserved medullary 
bone in the T. rex femur (the one that was in the
journals over the last couple of months). Still more to come in this form of 
preservation.

* Ken Carpenter and Christine Lipkin gave updates on the work on T. rex 
forelimb morphology and mechanical strength. Metacarpal III
is present, is a slender rod in some individuals, but a lumpier mess in others 
(like Peck's Rex). This and stress fractures in
furculae and the like suggest repeated injuries to these, and hence they were 
doing SOMETHING with them!!

* Kirk Johnson on the EXTREMELY good refinements of geochronology and 
chronostratigraphy of Hell Creek and related deposits. The K/T
boundary now has a super-well supported date of 65.51 +/- 0.3 Ma, to be 
replaced by an even BETTER refinement later this year. No T.
rex is older than 69.5 Ma, and they all well might be much younger: we may only 
be looking at a 1-2 million year range for that
species.

* Pete Larson supported the robust/gracile morphologies with some data plots. 
Looking good on these lines.

* Hans Larsson's most excellent 3D animation of kinesis in the skull of Stan: 
definitely some really interesting things going on in
tyrant skulls.

* Philip Manning's talk on locomotion had a lot of great details; most 
significant is the fact that nearly all tracks that we find
are NOT surface tracks, and most do NOT give us the actual foot size (since the 
shape and size of the print changes as it propogates
down different sedimentary layer). Hence speed calculations etc. from trackways 
must be used with much caution.

* Thom Carr showed updates on his ontogeny work in T. rex and A. libratus (G. 
libratus to me, but that's okay).

* Tom Williamson (and Thom Carr) discussed distribution of different tyrant 
species throughout western North America (but esp. the
American SW).

* Phil Currie's review of Canadian T. rex discoveries was also a review of some 
of his personal collecting history out in that neck
of the woods.

* Speaking of history, Brent Breithaupt summarized the history of T. rex in 
Wyoming in particular, and Neal Larson about T. rex
history over all.

* Greg Paul summarized tyrannosaurs as swift predators.

* John Happ discussed an interesting specimen of Triceratops with healed-over 
T. rex bite marks.

* Speaking of individual specimens, John Meyer and Kraig Derstler each 
described different specimens "Pete" and "Peck's Rex".
Incidentally, the latter is the infamous Rigby tyrannosaur. All you have to do 
is go to places with the mounted skeleton (for
example, the Maryland Science Center), to see that it isn't larger than other 
specimens. Also, Mike Henderson talked about "Jane",
the juvenile T. rex or Nanotyrannus (depending on your taxonomic scheme).

* Ralph Molnar examined jaw musculature in T. rex, but didn't dwell on the 
details (which, as he pointed out, would be better looked
at in the paper than in brief glimpses on screen).

* Bruce Rothschild and Kevin Donnelly and others looked at different patterns 
of pathologies found in tyrannosaurids.

* Bill Abler's talk was rather philosophical, and only got to tyrannosaurs by 
the very end, at which point he had run out of time.

* Marin Lockley's talk was also philosophical, but with a homeobox/heterochrony 
bent.

* For my guild talk, see SVP last year. For my predation/scavenging 
presentation, see my Step-Into-Reading book by Random House...
(Okay, this version had a lot more bivariate plots).

* Bakker's talk suggested that several adapations of the forelimbs and the 
pubic boot in theropods were developed for dominance
rituals that mimic mating habits.

I would say big themes out of the whole conference were:
* Variation: Document it! Only then we can start answering when is it 
taxonomic, and when is it ontogenetic.
* Pathologies: what do they say about the lifestyle of animals?


                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
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/
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796