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SVPCA 2000, part 1
Am now back from the 48th Symposium of Vertebrate Palaeontology
and Comparative Anatomy. This year the venue was here (Portsmouth)
which made travelling a bit cheaper. Thanks to organisation by Dave
Martill and Stig Walsh, this SVPCA was perhaps the most visually
impressive ever with a display of Luis Rey artwork, some of the
models from Walking With Dinosaurs (_Ophthalmosaurus_,
ornithocheiroid and _Koolasuchus_ head), an unbelievable display of
Santana and Crato Fm. fossils (including coelacanths and a complete
notosuchian) and a full skeleton of a new taxon of robust Liassic
plesiosaur. Isle of Wight collectors Mick Green and Keith Simmonds
brought along some stuff for display. Keith showed a complete
sauropod forelimb - it is one of four forelimbs (from two individuals)
found preserved vertically in the substrate. Apparently two same-sized
individuals (siblings?) got mired together and both died standing up.
Discussing the specimen with Paul Upchurch, it seems to be a non-
macronarian eusauropod (yes, Upchurch does use the term
Macronaria) with proportions suggesting it's even more basal than
_Cetiosaurus_. So... cf. _Jobaria_?:)
As always there was much socialising and parties that went on until 2,
3, 4 or 5 o'clock (depending on stamina and lack of regard for personal
health). The T-shirts featured my design (our new theropod, see below).
Was great to meet some new people for the first time (e.g. Adam
Yates, who you might have heard of). Talks and posters were
dominated by archosaurs with a substantial contribution from marine
reptiles, squamates and other diapsids. Fish were the losers with
something paulty like four talks - mammals were similarly ill
represented. I think I'll make a T-shirt that says "Theropods are the new
rodents". Personally I like mammals as much as reptiles and I'm not
happy to see groups underrepresented. Right now I cannot find my
abstract volume so am going to try and recall the presentations off the
top of my head. Where to start? Will review the conference in more
than one email. This is Part 1, the dinosaur one.
Max Langer: Postcranial anatomy and the diagnosis of Dinosauria.
Discussion of all the characters previously used to support dinosaurian
monophyly showed that, in Max' new tree, many of them (e.g.
additional of sacrals, fully open acetabulum) have evolved
independently in different dinosaurian clades (but dinosaur monophyly
still supported). Herrerasaurids were not theropods but whether
_Eoraptor_ was the sister taxon to Herrerasauridae or to
Herrerasauridae + Eusaurischia was controversial. _Guibasaurus_ was
sister to other theropods. As an aside, in the theropod tree
Coelophysoidea was paraphyletic because _Dilophosaurus_ was closer
to _Ceratosaurus_ + Tetanurae than to _Coelophysis_. I think Ollie
Rauhut has this result as well. Lots more stuff but I wouldn't like to
say without checking Max' abstract.
Adam Yates: Whither Sauropoda? New data from a British
Adam argued for a paraphyletic Prosauropoda where sauropods were
part of a clade that included _Lufengosaurus_ and _Massospondylus_,
_Melanorosaurus_ and _Blikanasaurus_. Much new data from a new
small _Thecodontosaurus_ specimen, probably a new species, has
allowed major reevalution. Skull reconstruction of new _Theco._
superficially much like _Eoraptor_. Hmmm. Adam has covered some
of this in DML emails and can obviously do a much better recap than I.
Eric Buffetaut: Triassic sauropods from Thailand.
New genus of Triassic (yes, Triassic) sauropod from Thailand:
includes material previously described as prosauropod. The femur is
the main reason for thinking that the animal is a sauropod - the fourth
trochanter is reduced and peculiar in shape. There is also a huge
humerus from a different site that might be from the same taxon.
Surprisingly, all of the material is huge and suggests an animal of 6-7
Kent Stevens: Digital models of joint articulation.
Much discussion of how one models zygapophyseal articulations on
the computer. Sauropods essentially have three different ways of
evolving zygapophyseal articulations in the neck. At previous
presentations, Kent has shown neutral neck poses for euhelopodids and
brachiosaurs. This time it was the turn of _Dicraeosaurus_: in Kent's
model, the dicraeosaur neck goes down and the head is nearly touching
the ground. The sauropod thus looks like a grazing bovid.
Angela Milner: 'Little and large' - theropods from the Purbeck.
The _Nuthetes_ teeth are most like those of dromaeosaurids. There is
also a partial metatarsal from the Purbeck that agrees in some features
with metatarsals of dromaeosaurids.
Darren Naish: An enigmatic new coelurosaurian theropod from the
Early Cretaceous of the Isle of Wight.
A new specimen of long-legged gracile coelurosaur from the Wessex
Formation is not synonymous with any of the named Wealden Group
theropods(nor with any other named taxon) and is a new taxon of
coelurosaur . It lacks derived features allowing allocation to any
recognised coelurosaurian clade but there are some similarities with
tyrannosaurids. Could it be a near-tyrannosaurid? Has fused nasals, a
distinctive maxilla and a proportionally short premaxilla. Arms are
long but powerful. Though the specimen is 4-5 m long, it is not an
Emily Rayfield: Muscles, mobility and jaws: more finite element
analysis of theropod skulls.
FEA of _Allosaurus_ shows that it had a relatively weak bite. Of
course there was more to the presentation that this but I don't
understand physics enough to repeat any of it. Emily showed photos of
'big Al': this specimen has an apparently very shallow lower jaw.. this
could be in agreement with the weak bite hypothesis (this is my
speculation, it wasn't mentioned by Emily).
Don Henderson: Show some backbone! Axial body mass distribution
and differing support strategies in theropod and ornithopod dinosaurs.
Don started his talk by stating his regret at involvement in the recent
_Nature_ paper: he only did the calculations and, quote, "Birds are
dinosaurs". Theropods and ornithopods have different ways of
supporting body mass.
Paul Davis: Fun with dinosaur fluff: interpreting Mesozoic feathers.
Paul claimed that _Archaeopteryx_ and _Confuciusornis_ only
provide evidence for contour feathers: no filoplumes or down. Also,
all but the very latest Cretaceous isolated feathers are contour feathers.
I believe this is wrong. I'm also troubled by the fact that Paul started
his talk by excluding nonavians - they cannot have feathers because
they are not birds. Paul also showed his 'alternative' avian phylogeny
(has been mentioned on this list before). It is controversial and strange
because avisaurids and a few other enantiornithines group with
_Patagopteryx_, hesperornithiforms, ichthyornithiforms and
neornithines: not with other enantiornithines. Gareth Dyke was
unhappy about this and asked for the data - Paul said it would be
provided in due course.
Gareth Dyke: _Protornis_ and the concept of 'centres of origin' in
Due to festivities the night before I missed this talk (and the following
one) but I did steal Gareth's overheads. Olson and other authors have
argued for the presence of some (modern) Southern Hemisphere bird
groups in the Eocene of Europe. Among these are various
caprimulgiforms, motmots (momotids) and, most recently, magpie
geese (anseranatids). Cladistic evaluation does not support some of
these identifications. The supposed European motmot (_Protornis_) is
a coraciiform, but apparently outside of the group including meropids
and motmots. The London Clay anseranatid is an anseriform but not an
anseranatid. I gather from the overheads that there was some
discussion of coraciiform monophyly but I don't know what the
Stig Walsh: Big chested birds - exciting new avian material from the
Neogene of Chile.
The first pelagornithid coracoid to be announced to the community
(though others are apparently known, they are secreted away in
collections and nobody is working on them). Is huge and has features
intermediate between pelecaniforms and procelariiforms. I missed this
talk and what I say here is taken from conversations I've had with Stig
about the bone.
David Norman: A new dinosaur from Transylvania.
A new genus has been recovered from material previously assigned to
_Rhabdodon_. Most of the postcrania seems to be of
dryosaurid/camptosaurid grade but the skull is distinctive: this is an
ornithopod trying to be a ceratopian (sort of). Posterior part of skull is
rather flattened dorsoventrally, there is a distinctive step in the lateral
side of the predentary as there is in dryosaurids. Ischium lacks an
obturator process, which is strange. On the cladogram the new taxon
fits between _Tenontosaurus_ and Dryosauridae. Intriguingly, the
cladogram Dr. Norman presented is pretty much a contradiction of
everything he's been saying for the last few decades: Iguanodontidae
was paraphyletic and _Tenontosaurus_ (which was monophyletic) was
closer to higher iguanodontians than to _Hypsilophodon_.
_Iguanodon_ (atherfieldensis + bernissartensis) was a clade and
_Altirhinus_ and _Eolambia_ grouped together. The new name
Thescelosauria was used for (_Thescelosaurus_ + _Bugenasaura_) +
Hypsilophodontia. Hypsilophodontia = _Hyp._ + _Tenontosaurus_ +
new taxon + Dryomorpha (Norman did not, and generally does not, use
That'll do for now. More to come if I have the time.
"I know the real world exists, I see it after 7 pm, but during the day I'm
in a different world, and I don't want to leave it"
PALAEOBIOLOGY RESEARCH GROUP
School of Earth, Environmental & Physical Sciences
UNIVERSITY OF PORTSMOUTH
Burnaby Road email: firstname.lastname@example.org
Portsmouth UK tel: 01703 446718