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SVP 2004 (talks - Thursday and Friday)
Thursday had a lot of non-theropod archosaur talks, coupled with a
session on mammals and another on taphonomy in the morning.
Jacqueline Kozisek described scapular facets on ribs as corresponding to
identification or the position and orientation of scapulae in the proximal
rib cage. Oddly enough, she did not discuss homology of the facets to
soft-tissue, which unfortunately I did not manage to get to ask her about.
Frank Varriale discussed unique dental action in *Triceratops* and
*Chasmosaurus,* using microwear patterns on teeth at various positions to
argue that strict orthal action in ceratopsids was unlikely.
Pete Makovicky reported on a new cladistic analysis of Ceratopsia using
a new partial skull of *Chaoyangsaurus* (less complete than the type, but
with better preserved portions) that seeks to resolve some issues. Less
discussed was a new taxon of basal ceratopsian.
Joshua Smith (the OTHER Josh Smith) reported on a new chasmosaurine from
Grand Staircase-Escalante, a "chasmosaur" closely allied to
*Pentaceratops.* Chasmosaurine phylogeny was discussed. Personally, *C.
mariscalensis,* *P. sternbergii* and this taxon may all be *Pentaceratops*
and those horn cores look an aweful lot like some I've seen in OTHER less
prominently featured taxa. Like *Ceratops.*
Dave Varricchio showed us the superb specimen of *Psittacosaurus* with
the nest of babies, apparently producing a menagerie, and all forms of
gathering such a brood were mentioned, so noone really got left out.
Alignment of the babies and postures suggest the assmebly was NOT
Hans-Dieter Sues gave me the saddest news since the beginning of SVP:
the type and paratype of *Caenagnathasia* have been misplaced, and are now
missing. I hope someone got a cast of them.... Anyways, dinosaurs from the
Kyzylkum at Dzhyarakuduk, mostly from the Bissekty, resemble those of the
Iren Dabasu of northeastern China and the Baynshire of southern Mongolia,
which were closely temporally allied. The faunal lists read almost the
same. New braincases of *Itemirus* are promising a distinct cranial
anatomy, and there are plenty of other fossils to make this a very well
Andy Farke decided to figure out why crest fenestration in
chasmosaurines are the way they are, so took a flat plate, modelled it in
FEA, and put muscles using the scars at the base of the crest that were
likely analogous to those in other animals, rather than stretching the
muscles over the fenestrae as others have done. The result was ... rather
fascinating ... as it supported more the idea of a compensation for
loading and stress response in chasmosaur frills than it does
"weight-saving." Andy has more modelling to do with regards to
*Triceratops* and stuff, so we should see some excellent work on anomolous
holes and fenestrae shapes.
I missed Kevin Padian's talk on species recognition via cranial
thingamajigs (trademark), and Steve Salisbury on epaxial muscles in crocs
(though I did kinda meet him by proxy in hanging out with John Conway,
Chris Glen, and Steve Wroe, fellow Aussies).
Jonathon Weinbaum reconstructed the skull of *Postosuchus,* which shows
some unique frontal, prefrontal, and lachrymal contacts, and this animal
is just begging to be modelled in FEA.
Chris Brochu showed us why his picture of *Allognathosuchus* is a
trashbasket. Alligatorines are a messy bunch of crocs, many with
convergent heterodont dentition tending to the globidont morphology.
Robin Whately showed an exquisite skeleton of a juvenile crocodyliform
from the Maeverano Formation of Madagascar, so detailed and tiny it was
likely a hatchling. Comparisons with extant juveniles confirms its
Alan Turner described yet another new species of the generalist
notosuchian *Araripesuchus* (and you know, eventually someone's gonna try
to split these species up...), this time from Madagascar. I love
Jean-Pierrer Billon-Bruyat gave a fascinating summary of work on a set
of *Pteraichnus* tracks that show a foot-first, then down to all-fours
landing pattern in a pterosaur, and subsequent quadrupedal walking. Tow
claw scratch-marks aside, very fascination implications, especially since
one of the authors of the abstract at the time I think still considers
pterosaurs to be bipedal.
Dave Unwin showed that pterosaur juveniles, even without epiphyseal
ossification or elaboration in joints, had limb proportions that would
mechanically allow them to fly well.
I did not stay for the ichthyosaur talks, though I think I should have.
At the same time, Stephen Wroe was discussing bite forces in mammals,
Karen Sears was analyzing rapid development and evolution of chiropteran
wing digits, thereby showing that there needn't be a very recognizable
transition series in the fossil record, the ancestral bat may look like a
proto-lemur or colugo.
The afternoon session was short, due to the poster session held later.
I was a coward and didn't go. They were faunal talks in Mesozoic and
Cenozoic times, and a set of talks of fishes....
Of course, unlike the poster session, this was a massive showcase and
there were aisles packed one end to the other. Some posters got a lot of
attention, some less that most. The student poster session was also there
at the time, and it was just as much of a draw. Included in all these were
several fascinating talks on baby sauropods with interesting braincases,
what *Revueltosaurus* might actually BE, perspectives on ceratopsian
stance, a new but unsurprising phylogeny of Ornithischia and the most
complex one conducted to date, relating the French and Bavarian
*Compsognathus* and compsognathids in general to one another, a new
sauropod from Mongolia, neck flexibility in birds with and without muscles
attached, armadillos and *Ernanodon,* reassessing *Procompsognathus,* a
chart of carpal loss and transformation, and lots and lots of mammal
Unlike the previous day, there were no late events, special features,
etc. (we went to the DMNS), Thursday and Friday were "rest" days; I got
TWO hours sleep total Thursday night. Yay.
Friday morning comes as a shock, and its off to the show.
Okay, so I missed Sean Faul's talk on *Hypacrosaurus,* oops.
Casey Holliday discussed anatomical domains in *Majungatholus*' skull,
and applied the practice of potential anatomial variation in braincases
and more external areas as an effect of the transition between various
domains, so there is plenty new space for phylogenetic information to be
Sebastian Apesteguia could not make it, so Pete Makovicky presented the
talk on *Bonitasaura,* which was essentially the same as the paper.
Alan Coulson talked about a new Ruby Ranch Cedar Mountain brachiosaurid,
but I fudged the details slightly, I don't remember why.
A juvenile herd of *Diplodocus* is fascinating information, Tim Myers
reported, showing age-segregation in sauropods. Remember Walking with
Dinosaurs and the herds of sauropods in distinct age-classes? Not so much
Jeff Wilson described ongoing research into *Nemegtosaurus* cranial
anatomy, both showing a lower jaw similar to *Bonitasaura,* the
possibility of a coronoid in *Bonitasaura,* and the lack of a
corresponding upper guillotine jaw.
Ruben Martinez' talk was cancelled.
Alex Kellner described what Matto Grosso is like ... it's not hiking
through badlands and dry outcrops ... no ... you have DREDGE areas and
treck through jungle and rivers to get where you want to ... the jungle
herds YOU. Yet another sauropod....
I skipped over the post-break talks until I caught Spencer Lucas'
reassessment of the Kirtlandian land-vertebrate age, why it shouldn't be
called an "age," and how everyone is essentially wrong in thinking about
biostrat ... especially Lehman.
Julia Heathcote ... I swear, she almost got a standing ovation, or at
least that's what the clapping suggested to me. Brilliant talk, using
coordinate points analysis on jugals and nasals and tracking them across a
long series of ornithischian (mostly iguanodontian) taxa. And she was
quite clear when she used _the Dinosauria_'s drawings (mostly by Karol
Sabbath) as a source, that she'd repeat the process from photos, and add
more taxa; but it became clear that a quite distinct transition in species
occurs through gradual jugal and nasal transformation, and that there is a
phylogenetic signal is gradual elongation of portions of bone.
I missed Motani Ryosuke's talk, but it was almost lunch, I was hungry,
so were my mates, and off we went.
Ryan Ridgely presented the third of the *Majungatholus* talks, regarding
modelling techniques this time.
William Parsons discussed ontogeny of *Deinonychus,* using new specimens
from Oklahoma that show for the first time a nearly complete skeleton in
one specimen, largely limited in other specimens to fragments. While he
used the classic Ostrom figure with the allosaur-head and odd-pubis (not
the coracoid), he showed there was a nice distinction among specimens
known, but this new one was still the best.
Eric Snively added to the models done by Molnar (BFA) and Rayfield (FEA)
by modeling the nasal alone in thin-spline analysis and showing how it's
curvature and cross-sectional structure prevented various forms of
distortion, despite pneumatic invasion. In essence, it may have been the
keystone of tyrannosaur cranial performance.
Greg Paul presented some interesting thoughts on tyrannosaur speed,
repeated past remarks and supporting new ones with a model of running.
While Greg did not respond to the mathematical figures in Hutchinson, he
DID bring up a good point: while energetics may not have much to do with
performance via muscle mass, general homeothermy and energetic behavior
may affect speed by timing and power muscles exert, so an animal with a
crouching stride or upright stride may still be able to move relative
fast, with the general thesis that energetics have been a tad overlooked.
David Smith discussed the braincase of the Crystal Geyser therizinosaur,
which shows some very interesting anatomy, and discussed its importance in
the role of pneumatization, mode of pneumatic progression, and
Ken Lacovarra discussed an enourmous sauropod femur from Para Aike,
Scott Hartman looked at the fore and hindlimb articulation and carriage
of hadrosaurs, showing that limbs are always flexed to some degree, never
straight or "elephantine" (though elephants also flex their joints at all
times during the stride, unlike us humans), and showed an oddly
ungulate-like action for the forelimbs in *Brachylophosaurus.* The old
paradigm, two legs are better for running, and four-legs slower and more
"stable" for walking is likely wrong in this case.
In the Friday poster session, there were evore more vast throngs of
people, oggling the fun and often interactive displays. I talked to Laurie
McWhinney and Torsten Sheyer about ankylosaur scute pathology, not a far
way down from Mateus' new dwarf sauropod from Oker (which is a really
fascinating animal), Leon Claessens presented new ideas about pterosaur
prepubes the next aisle over, and all and all it was a great session.
I managed to not set my alarm clock and got 10 hours of inadverdantly
Jaime A. Headden
Little steps are often the hardest to take. We are too used to making leaps
in the face of adversity, that a simple skip is so hard to do. We should all
learn to walk soft, walk small, see the world around us rather than zoom by it.
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
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