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RE: Burpee Conference (LONG)



  Concerning the study by Williamson and Carr, below,
what evidence is there that T. rex ranged as far south
as Mexico? Of course, it wouldn't be surprising if it
did, since tyrannosaurs are known from the
Campanian-early Maastrichtian of Mexico. Maybe they
just assumed T. rex was there, since its presence is
now confirmed in adjacent NM.

--- "Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>
wrote:

> 
> Let's see, here's a brief summary:
> After a brief introduction by Lew Crampton and
> Michael Henderson of the Burpee, and Mike Parrish of
> Northern Illinois University, we
> got straight into the focus of the event: Jane the
> tyrannosaur. (I got drafted at the last minute to
> serve as a co-moderator for the
> morning...)
> 
> Peter Larson continued to put forth his case for the
> reality of Nanotyrannus as a genus, based primarily
> on the presence of a higher
> tooth count and a difference in tooth shape than
> Tyrannosaurus rex (and of the supposed
> "Tyrannosaurus X", Bakker's proposed second
> species of the Big Guy), as well as the presence of
> a few different pneumatic structures (such as the
> lateral pneumatic foramen on
> the quadratojugal of Jane, the Cleveland skull, and
> no other tyrants).
> 
> Currie (with Mike Henderson, Jack Horner, and Scott
> Williams as coauthors) showed that the change in
> tooth shape is in fact probably
> just allometric, as is the purported difference in
> the glenohumeral joint. Phil still considers
> lancensis a distinct species, but
> almost certainly the sister taxon to Tyrannosaurus,
> and thus (although he didn't say this out loud) it
> would be Tyrannosaurus
> lancensis.
> 
> Tyler Keillor showed the work he did on the
> wonderful Jane head restoration. He presented some
> VERY persuasive arguments for a
> varanid-like lip and gum arrangment in tyrannosaurs
> and other theropods. Basically, the line from the
> enameled to non-enameled tooth
> surface is the gum line, but the gum line was well
> above the maxillary or dentary surface. When closed,
> even a T. rex may have had
> hidden teeth and a lizardy-lip.  He also got several
> paleoartists to contribute their own different
> illustration of Jane.
> 
> Mike Parrish (with Mike Henderson and Kent Stevens)
> looked at the ontogenetic changes in the
> glenohumeral joint in tyrants.
> Basically, they had proportionately longer humeri
> and greater lateral excursions as youngsters than as
> adults.
> 
> Kent Stevens (with Mike Parrish) showed via
> DinoMorph where the ontogenetic changes are in the
> tyrant skeleton, by morphing Jane
> into Stan. Rather than simply holding the femur as a
> unit length, you used the body length as the unit
> and watched the changes in
> the various parts. Also, he showed some of the
> sitting and standing sequences from the BHI
> meetings.
> 
> Thom Carr discussed his ongoing work in
> tyrannosaurid ontogeny and the application of
> cladistic algorithms as a test for these. (Ron
> Tykoski is doing similar work with coelophysoids, as
> seen at last year's SVP). As no surprise, but nice
> to document, juveniles tend
> to be placed basally to adults because they have not
> developed all their autapomorphic traits.
> 
> Hurum (with Currie and Badamgarav) discussed growth
> series of Tarbosaurus and Daspletosaurus. 
> Intriguingly (for me, at least), the
> lacrimals of youngsters of these are more
> albertosaurine-like than the adult. Many beautiful
> specimens.
> 
> Erickson, Makovicky, Currie, Norell, Yerby, and
> Brochu's famous life history paper was presented,
> but none of them presented it!
> Instead, Albert Prieto-Marquez did so, even though
> he works on tyrants one trophic level removed (i.e.,
> hadrosaurids). By the way,
> Jane was 11 when she died.
> 
> Then, lunchtime!
> 
> Stephen Hutt (glad I could finally meet him!)
> discussed the history of Eotyrannus' discovery, the
> weirdness of the anatomy (such as
> its non-tyrannosaurid like pneumatic nasals), and
> the fact that he hadn't thought it was a
> tyrannosauroid at first. He did mention
> he first wanted to call it "Fusinasius", but was
> convinced otherwise by his coauthors (there was at
> least one other proposed name,
> but unless Hutt or one of his coauthors reveals it,
> I'm bound to secrecy). New material continues to be
> discovered.
> 
> Walter Stein (with Mike Triebold) discussed their
> tyrannosaurid nicknamed "Sir William". Most of what
> he presented was travelogue
> and questions about the age of the specimen, but
> what has shown suggests that this (probably upper
> Judith River Fm.) specimen is a
> tyrannosaurine close to the origin of Tyrannosaurus.
> Incidentally, this specimen was used in the Erickson
> et al. T. rex growth
> curve.
> 
> Tom Williamson (with Thom Carr) discussed a specimen
> of T. rex from an artificial lake in New Mexico.
> Enough material is known to
> document that it is indeed Tyrannosaurus rex, which
> appears to have ranged from Canada to Mexico.
> 
> Mary Schweitzer's talk (with Jennifer Wittmeyer and
> Jack Horner) was similar to her presentations at
> last SVP and at BHI: the
> discovery of the medullary bone and soft tissue
> preservation in MOR 1125. She said that there will
> be new spectacular stuff at the
> next SVP...
> 
> Larry Witmer and Ryan Ridgely's talk on CAT scanned
> tyrant skulls was damned good! They reinterpreted
> various features in the older
> Nano and Sue scans (for instance, there are nasal
> turbinates in the "olfactory bulbs", which are
> actually olfactory chambers). The
> biggest surprise, for these authors and the
> audience, was how different the Nanotyrannus was
> internally from the adult rex
> specimens. The possibility of ontogentic change is
> not ruled out, but if so there were lots of changes
> in there.
> 
> Grant Hulburt updated previous work on
> encephalization of dinosaurs. T. rex EQs are well
> below recent birds, but among the highest
> of non-maniraptoran dinosaurs. (Troodon,
> Bambiraptor, and Dromiceiomimus fell within Recent
> birds).
> 
> This Holtz guy, who was 40 years and 3 days old at
> the time of the presentation, discussed his latest
> phylogenetic analysis of
> coelurosaurs with a focus on tyrants. I found two
> alternative arrangements on the major basal clades
> (either compys + [tyrants +
> [ornithoms + maniraptorans]] or tyrants + [compys +
> [ornithoms + maniraptorans]]), two alernatives for
> Maniraptora (either the
> arrangement in Dinosauria II or therizinos +
> [alvarez + [oviraptors + [birds +
> deinonychosaurs]]]). More importantly for these
> talks, though, I recovered Dilong, Aviatyrannis,
> Eotyrannus, and Dryptosaurus as basal
> tyrannosauroids, and Appalachiosaurus as the
> sister taxon to Tyrannosauridae. Also, Tanycolagreus
> came out as the basalmost tyrannosauroid.
> 
> Stephen Brusatte (with Paul Sereno, who is off in
> Niger doing archaeological [NOT a typo!!] work), did
> a nice metacladistic analysis
> using CharacterSearch to see how two different
> phylogenetic analyses differ. The subjects were the
> Currie et al. (2003) and Holtz
> (2004) tyrannosaurid phylogenies. He made our
> matricies jump through lots of different hoops, and
> showed (for instance) that my
> characters record more structure but are more
> homoplastic, while Phil & co.'s preserved less
> structure but were more invariant.
> 
> Doug Nicholls (with William Harrison and Mike
> Henderson) discussed the palynological and paleomag
> dates 
=== message truncated ===



                
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