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Re: dino symposium?
I made it to most of the first day of the symposium. There were indeed a
very small number attending (35 including speakers would be my quick
estimate) Here's a quick overview of the talks:
Jeff Wilson gave the first talk of the day, with an overview of questions
and trends in dinosaur systematics. Sadly, I missed this first talk and
thus can't comment much further (because security said my pocket knife was
too large to hold at the desk and made me take it back to my car).
Matt Lamanna followed with a discussion of dinosaur paleobiogeography. He
spoke mostly on work done looking at possible vicariance at the continent
level, but also mentioned that more attention was beginning to be given to
finer scale structuring (using the example of possible highland/lowland
structure on the west coast of the NA Interior Seaway).
Stephen Gatesy spoke on functional and biomechanical analysis in dinosaurs.
Specifically, he focused on his work looking at trackway production in
mudflats using computer models and extant bird models. He showed some
output examples from his model (in 3D no less) which demonstrates, among
other things, that supposed 'reversed hallux' tracks in early Mesozoic
sediments are actually produced quite normally by a facing hallux toe
submerging in mud.
Greg Erickson spoke on his work reconstructing dinosaur growth patterns.
This project was also presented at SVP, as I recall, and involved using
growth series of long bones in various taxa (from which different ages are
known) to reconstruct growth curves. In (very) short, growth lines (which
do appear in most taxa, despite the bones also being high vascularized)
along with mass extrapolation were used to determine annual growth. Growth
rates in the exponential phase were found to be generally higher than most
modern ectotherms, but generally lower than extant eutherians or birds
(though some were around metatherian rates).
Hans Larsson spoke next on the use of developmental evolution techniques in
paleobiology, and its importance to dinosaurs in particular. This was
another general review talk, by and large, and he made the strong point that
it works both ways: not only can developmental biology help shed light on
the evolution of extinct taxa, but fossil organisms can help supply data
towards understand development (and how it evolves) in extant species.
Matt Carrano (host) gave a talk on body size evolution in dinosaurs. He has
found an overall trend towards larger size in the group over time, with some
evidence that it is an active trend rather than a passive one. However, he
pointed out that incomplete phylogenies may be confounders in this latter
aspect, since missing branching events will make small derived forms appear
to be small but basal. He used both nodal depth and age measures. While
most taxa followed the general trend, two clades showed a decrease in size
over time: titanosaurs and maniraptorans. He also showed briefly the lack
of overlap between the mammalian body size range and dinosaur size range;
which mammals 'filling in' the gap left behind as the dinosaur average moved
ever upward (and then filling in rapidly after the K/T). Mentioned that
juvenile dinosaurs would have had a size range implying rather higher
interactions with mammals. Also pointed out the interesting tidbit that
mammals and dinosaurs cover a similar range of size factors (about 9
factors), but gravitate towards opposite poles of the spectrum; mammals tend
towards smaller sizes (with a small average) and dinosaurs tend towards the
larger end of their range.
Joanna Wright gave an overview of the history and current study in dinosaur
trackways. She focused to some extent on the possible questions to be
answered by trackways, giving a general look at targets and directions to be
taken with such data. She ended with a bit of locomotion modeling work she
in currently involved in, attempted to match computer walking models with
trackways in several taxa.
Scott Sampson looked at the functional and behavior implications of 'bizarre
structures' in dinosaurs. He looked especially at horns and nasal
elaboration, though he also took a quick look at ceratopsian crests and
pachycephalasaur domes. His work on dinosaur nasal structures has convinced
him that they did not support trunk apparatus in any dinosaurian taxa, but
that temperature regulation was a distinct possibility for groups such as
large ornithopods and ceratopsians. His feeling seemed to be that most of
the structures seen across the dinosauria were for sexual display and
combat, a few were possibly defense devices, and others (such as enlarged
noses) has a physiological function.
Elizabeth Rega spoke about paleopathology, with an emphasis on her work on
'Sue'. She was quick to point out the difficulty in actually assigning
diagnosis to paleopathologies. She also commented that most diseased
individuals seen were likely relatively healthy; frail individuals would not
heal and would die, and especially healthy animals would not be ill in the
first place. The irony, then, is that frail animals and hyperrobust animals
look the same as fossils. Despite the public press, 'Sue' was probably
pretty healthy (at least healthy enough to heal the broken bones and
erosions). The holes in the skull are likely NOT bite marks; they are
consistent with erosions from fungal parasites common as natural flora of
the mouth (and which cause similar cavities in extant animals).
Paul Barrett closed the day with a talk on dinosaur feeding and diet.
Unfortunately, I also was absent for this talk, as I had to leave just
before to make it back to Charlottesville.
On 12/16/03 8:20 AM, "Ken Carpenter" <Kcarpenter@dmns.org> wrote:
> I am surprise that no one has reported on the dino symposium at the
> Smithsonian. Didn't any one go? I heard turn out was very low, like maybe
> 30-40 people, including the speakers. If true, it definitely sounds like their
> PR department did a poor job getting the word out.