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Re: II CLPV talk summaries: Day 2
the presumed sprawling stance (which she inferred
from the non-perforated acetabulum).
Sterling Nesbitt gave one of my favorite talks of the conference. He
showed that Shuvosaurus is not an ornithomimid (no real surprise
there), but is rather a derived suchian.
So far, so good...
And he demonstrated this pretty convincingly, since he has
a number of specimens with post crania conveniently attached to skulls.
For those of you who haven?t
seen this thing, it is insanely cool. It?s like a crocodile-line
archosaurs trying its best to be a prosauropod, complete with long
flexible neck. Even weirder, it is probably an obligate biped.
ROTFL!!! So it _looked like_ an ornithomimosaur! Chatterjee is a wise
Likewise, he showed that Revueltosaurus teeth are not those of a
Triassic ornithopod, but rather come attached to a suchian skull.
Recently published -- unfortunately without any hint at the phylogeny of
Suchia. Has anyone looked into that since the mid-late 90s?
But first Paul Sereno gave a talk that had two main points. One is
that he is helping to create an online database for sharing and
analyzing data matrices used in phylogenetic analyses.
So he's reinventing TreeBASE http://www.treebase.org/treebase/index.html?
He showed images of software that could show what percentage
of different matrices used the same characters, if they used disagreeing
character states, and (literally) dozens of other useful tools for trying
to mine useful comparative data from cladistic data sets.
Wow. So he's improving on TreeBASE...?
A (non-comprehensive) list includes
Eucoelophysis, which they feel pretty strongly is a silesaurid.
Which makes the name EU-coelophysis ironic, to say the least.
Let's hope it's still hollow :-)
Gojir[a]saurus they feel is a chimera
So... good I don't use it for my thesis (because the vertebrae are
made up of theropod
material and Shuvosaurus (or shuvosaur-like suchian) material.
Finally, they think Technosaurus is a silesaurid as well.
Watch silesaurids, it seems to be raining them lately?
As soon as people know what to look for, silesaurids and shuvosaurids turn
Max Langer gave a talk that was ostensibly on the first ornithischian
body fossils from the Triassic of Brazil. When the first slide came
up, however, it was obvious that he has a bone-bed of silesaurid-like
material as well.
He did note the similarity to Silesaurus, but rather than
concluding that his new animal(s) are not dinosaurs, he
inferred that Silesaurus is itself a basal ornithischian.
Reminds me of something... but then I still haven't looked at the femur and
pelvis anatomy, and it's not likely that I'll do anytime soon.
Diego Pol presented data from new specimens of Mussaurus. [...]
Claudia Mariscano gave an overview of the abundant dinosaurimorphs
footprints her team has found in Argentina. She feels that the inherent
difficulties in taxonomic identity (i.e. correlating with body fossils) in
intractable at this point, but does feel that the ichnofossil record
argues persuasively for an early evolution and radiation of dinosaurs than
the body fossil record shows.
Even when the ghost lineages are taken into account? *Saturnalia*, the
basalmost known sauropodomorph, is as old as *Staurikosaurus*, one of the
basalmost known saurischians, and at least as old as *Pisanosaurus*, the
oldest and basalmost known ornithischian (assuming that the even _younger_
silesaurids are not ornithischians -- if they are, they're no doubt more
basal than *Pisanosaurus*)...
He also concluded that [...]
the heal pad evolved further down the sauropodomorph tree than is
usually thought. That last one I found really intriguing, as it had
never occurred to me to put heal pads on prosauropod hind feet, but
some of the tracks did look convincing.
Wasn't it recently said that *Plateosaurus* was "semiplantigrade" like a
sauropod, based on the shape of the astragalus? In that case it would have
needed a heel pad.