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SVPCA 50, REPORT III



Alas, parental and other duties have so restricted what time 
I have available for research/email etc that I now face the 
dreadful prospect of being literally _days_ out of date with 
the latest news in dinosaur research. Some quick notes 
before I get back to reporting SVPCA 50...

This just in..

Modesto, S. P., Damiani, R. J. & Sues, H.-D. 2002. A 
reappraisal of _Coletta seca_, a basal procolophonoid 
reptile from the Lower Triassic of South Africa. 
_Palaeontology_ 45, 883-895.

Re: Oli Rauhut's new paper on the dinosaur teeth from Una 
(Cuenca, Spain) in _Cret. Res._ 23.. Assuming that what is 
in the final paper is similar to what was in review versions, 
one significant thing in this paper not mentioned by Ben is 
that Oli suggests that paronychodonts are 
archaeopterygiforms.

Re: SVPCA 50, last time I got as far as Fastnacht's talk on 
dsungaripterids in the pterosaur section. This time round 
let's see if I can get through dinosaurs...

DINOSAUR TRACKS

Two talks focused on trackways. Jesper Milan looked at 
undertrack preservation using live emus as trackmakers. 
Anatomical details disappeared in transmitted tracks while 
the track shape remained recognisable. Whether undertracks 
ever form has recently been contested by Nadon. 

Peter Griffiths talked about a fantastic trackway from 
Crayssac where a small theropod (approx. hip height 47 
cm), running at approx. 4 m/s, suddenly executed a dynamic 
turn and then clearly ran back 180 degrees to its original 
line of travel. Why it performed this abrupt about-turn is 
unknown BUT it does so at the exact same point as another 
dinosaur trackway is observed (thus implying avoidance 
behaviour). At the turning point, the tracks show that the 
animal rotated rapidly on one foot. As it did its tail swiped 
along the ground, cutting into the sediment and leaving a 
prominent trace. The turn was clearly abrupt, dynamic and 
executed 'on a sixpence' thus, contra Carrier et al's recent 
paper about inertia preventing long-tailed theropods from 
being rapid turners, the trackway indicates that long-tailed 
dinosaurs _could_ turn abruptly, and used their tails 
dynamically as they did so.

GENERAL DINOSAUR STUFF

Michael Parrish discussed rib angulation and 
scapulocoracoid position in dinosaurs. Ribs should be swept 
backwards, obviously. Looking at sauropod ribs, Parrish 
noted concave areas on the dorsal surfaces of sauropod 
thoracic ribs that appear to correlate with scap-coracoid 
position. Adjusting the pectoral girdle accordingly, he 
found that the scap-coracoid was located a bit more 
ventrally than normally recontructed, and consequently that 
the sternal plates became somewhat 'flattened out' and lay 
closer to the ventral surface of the thorax than normally 
thought. The implications this has for dinosaurian 
musculature were discussed.

Angela Milner showed that proteinaceous material 
(specifically proteoglycans) could be detected in 
_Iguanodon_ bones from Smokejack's Pit, Surrey. This is 
the first report of proteoglycans from fossil bone.

Darren Naish discussed newly recognised material of 
_Eotyrannus_ and its possible implications, a large 
brachiosaurid cervical vertebra that shares some features 
with _Sauroposeidon_, and the palaeopathologies seen in 
the holotype of _Neovenator_ and the _Iguanodon_ found 
with it. Both animals were bristling with injuries and the 
_Neovenator_ preserves evidence of osteoarthritis: the first 
report of this in Dinosauria excepting _Iguanodon 
bernissartensis_ and chickens. Judging from the feedback I 
got, this was technically the weakest and stylistically the 
crappest SVPCA talk of them all. Still, you gotta laugh.

Colette Cherry spoke about bone histology in 
_Thecodontosaurus_ and Anusuya Chinsamy reviewed 
bone depositional rates among Dinosauria. Depositional 
rates are significantly affected by environmental conditions 
and, following experiments on quails, I _think_ Chinsamy's 
point was that the short development time of extant birds 
may cut down on the variation (development of LAGs etc) 
seen in the bone development of other dinosaurs. She did 
state that LAG development was not simply a 
plesiomorphic thing (contra Padian et al.) seeing as 
herrerasaurs apparently lack LAGs.

SAUROPODOMORPHS

Adam Yates reviewed the prosauropods of the Lowenstein 
Formation (better known as the Stubensandstein) of 
Germany. Employing a specimen-based analysis of 34 (I 
think) characters, _Sellosaurus gracilis_ was found to share 
derived characters with _Plateosaurus_ and thus was sunk 
into the latter genus. Meanwhile, _Efraasia_ was resurrected 
from _Sellosaurus_ and lacks the derived characters of 
_Plateosaurus_ (and in fact of the Plateosauria). It was 
shown that _Teratosaurus minor_ has the same diagnostic 
characters as _E. diagnosticus_, so _minor_ is the oldest 
available name for the species. In Adam's phylogeny, 
_Efraasia_ is a stem-sauropodomorph (as is 
_Thecodontosaurus_ and _Satunalia_ I think [couldn't copy 
down the whole cladogram fast enough]) while 
_Riojasaurus_ + Plateosauria form a monophyletic 
Prosauropoda that is sister to Sauropoda.

Kent Stevens talked about a specimen close to my 
proverbial heart, an articulated, complete sauropod forelimb 
from the Isle of Wight discovered by local collector Keith 
Simmonds. Discovered adjacent to other vertically-mired 
sauropod limbs (see my previous comments on these 
specimens in the writeup for the Portsmouth SVPCA 
meeting), this specimen definitely lacks a pollex claw and 
carpals, has an ulnar olecranon and has tightly bundled 
metacarpals in which mets I and IV (nearly touching at the 
back of the hand) may have worked as a functional heel. 
The big surprise is the identity Kent proposed for this form 
(it wasn't a surprise to me as I'd had it discussed to me at 
length prior to the talk, but anyway...): based mostly on the 
proportions, he argued that it was a diplodocid, and more 
specifically was closest to _Apatosaurus_. The glenoid was 
1.8 m off the ground suggesting a total length of 9.8 m, so if 
this is an apatosaur it's a dwarfed, thumbless form with 
more columnar limbs than Jurassic diplodocids. However... 
Paul Upchurch was not happy with this and, as you may 
gather from the lack of a pollex ungual and ulnar olecranon 
(and other characters), argued that a diplodocid ID was 
unlikely and that the specimen seems instead to be a basal 
titanosaur. 

Eric Buffetaut showed how new skull material of 
_Phuwiangosaurus_ definitively links it with the 
nemegtosaurids (e.g. _P. sirindhornae_ has the same caudal 
quadrate fossa as does _Quaesitosaurus_, slit-like 
supratemporal fossae etc) and is in agreement with a 
titanosaur affinity for nemegtosaurids. Eric also showed that 
_Huabeisaurus_ agrees with _Phuwiangosaurus_ in many 
features and is probably a close relative. _Tangvayosaurus_ 
is also similar. 

I initially thought Eric was talking about _Hudeisaurus_ 
(which resulted in a very confused conversation with 
Sasidhorn Khansubha). The paper presenting these results 
is...

Buffetaut, E., Suteethorn, V., Le Loeff, J., Cuny, G., Tong, 
H. & Khansubha, S. 2002. A review of the sauropod 
dinosaurs of Thailand. In _The Symposium on Geology of 
Thailand, 26-31 August 2002, Bangkok, Thailand_, pp. 95-
101.

Jeff Wilson discussed trends of neck elongation among 
sauropods. Early sauropod evolution is characterised by 
duplication and incorporation events (i.e., eusauropods 
incorporated a dorsal into a cervical and exhibit a 
duplication of two cervicals relative to the ancestral 
condition) but, excepting diplodocids (which incorporate 
two more dorsals into cervicals), later sauropod clades are 
not characterised by any neck-lengthening events. Instead, 
individual genera seem specialised for their own neck 
lengths.

Theropods and ornithischians to come in next email...

Happy birthday to me.

-- 
Darren Naish
School of Earth & Environmental Sciences
University of Portsmouth UK, PO1 3QL

email: darren.naish@port.ac.uk
tel: 023 92846045