SVPCVA 2000, part 2

[darren.naish@port.ac.uk]

Onto my patchy garbled recollections of SVPCA. Apologies if I have 
misrepresented any talks (I did a particularly bad job with Adam's and 
Max'). Yes there is an abstract volume. It was edited by Stig Walsh but 
is officially anonymous, being one of those volumes only handed out 
at conferences. I suppose copies can be obtained from us (the 
organisers) but they will have to be photocopies I'm afraid.

In the last email there were a few dinosaur things I neglected to 
mention. Phil Manning, in his talk about new Yorkshire coast 
discoveries (mentioned further below), recounted the discovery of 
previously unnoticed _Scelidosaurus_ material in the collections of a 
Yorkshire museum (possibly Whitby). The material was collected in 
the 19th century. What will interest Jim Kirkland (hint) is that the 
material - a few caudal verts - had the scutes preserved in the GSP style 
(i.e. scutes stick up vertically from dorsal surface: do not project 
laterally). Please pass this onto Jim if you are in current 
correspondence with him. On the subject of scelidosaurs, this is out....

Martill, D.M., Batten, D.J. and Loydell, D.K. 2000. A new specimen of 
the thyreophoran dinosaur cf. _Scelidosaurus_ with soft tissue 
preservation. _Palaeontology_ 43: 549-559.

Eric Buffetaut's new Triassic sauropod (mentioned in part 1 email) is 
_Isanosaurus_, the new taxon just described in _Nature_. The new 
theropod I spoke about is, sigh, the 'cat-like' coelurosaur covered in the 
national press last year. As I have explained before the 'cat-like' thing 
was a total misunderstanding by a journalist.

Ok, onto the goodies. This time I'll do pterosaurs and marine reptiles.

PTEROSAURS

Dave Unwin: _Sharovipteryx_: what can it tell us about the origin of 
pterosaurs.

_Sharovipteryx_ is more pterosaur-like than previously noticed: there 
is a patagium between the femur and thorax and there are aktinofibril-
like rods in the patagia that are IDENTICAL in size, shape and form to 
aktinofibrils of pterosaurs. The femur is longer than the tibia, there are 
elongate caudal verts and there are 4 sacrals. The foot is pterosaur-like, 
the neck is long. Lots of nice photos. In parsimony analysis, 
_Sharovipteryx_ is a prolacetiform closest to _Macrocnemus_. Unwin 
ran David Dilkes' archosauromorph data set and included pterosaurs: 
they are prolacertiforms in a clade with _Protorosaurus_, 
_Macrocnemus_ and _Tanystropheus_ (and _Tanytrachelos_ IIRC). 
Unwin thus supports the idea that pterosaurs are prolacertiforms and 
NOT archosauriforms. 

Dino Frey: Pterosaurs, flying machines and the first 'bottom deckers' in 
the world.

A new Crato Fm azhdarchid - this is the same specimen that preserves 
complete feet and has strongly curved unguals and a scaly food pad 
(discussed at SVPCA in Edinburgh last year) - has proved strikingly 
complete and well preserved. The whole of the wing and leg (from at 
least one side) are there. It is STRANGE. Legs are very very long, 
wings proportionally short. The scap-coracoid is constructed such that 
the glenoid is very low down in position (no they do not have it the 
wrong way up) and the wings would have been positioned very low on 
the body. Dino explained at great length the difference between 'top 
decker' and 'bottom decker' aircraft: 'bottom deckers' are difficult to 
fly, more manoeuvrable but unstable. Azhdarchids (or at least this new 
taxon) seem to have been able to hold the wing in a shallow V and thus 
confer great stability during flight. The abstract is lengthy and there is a 
lot of aerodynamic discussion that I will not recount here. This 
morphology is unique for flying vertebrates.

Lorna Steel: Internal helical reinforcing of the pterosaur wing skeleton.

X-shaped cross-bracing inside pterosaur long bones is a method of 
internal reinforcing. Cross-struts in long bones are remodelled during 
life. 

MARINE REPTILES

Will have to be brief as I've run out of time.

Mark Evans: The cheek of it: the skull of the plesiosaur 
_Muraenosaurus_... revisited.

New specimens and interpretations allowed Mark to update the skull 
reconstructions he'd produced in 1997 and 1999. A new specimen is 
large and chunky: bigger (about 1.5 times) than previous specimens. 
Individual variation or a new species? New specimen includes cheek 
region (previously unknown) plus parts of suspensorium, lower jaw, 
frontals etc. _Muraenosaurus_ is no dainty slim-headed predator: its 
skull is deep and quite robust with a prominent sagittal crest and a 
peculiar 'broken nose' effect on the frontals (a rugose bump rostral to 
the orbits, dorsal to nares). This is not an artefact (is present in other 
specimens). Not mentioned in the talk was the fact that the external 
nares are rostral to the internal nares (reverse of condition now well 
known for plesiosaurs). Despite the large size of the new specimen, it 
was less well grown that the other, smaller specimens! In many 
respects _Muraenosaurus_ is identical to cryptoclidids.

Les Noe: _Pachycostasaurus dawni_, a Callovian pliosaur (Reptilia, 
Sauropterygia): is the new genus a juvenile?

Les showed lots of slides of the skull and how he'd managed to 
reconstruct it. It is not a juvenile of a named pliosaurid taxon.

Richard Forrest: Plesiosaur necks, service cores and statistics.

Inspired by Ken Carpenter's recent elasmosaurid phylogeny papers, 
Richard took issue with some aspects of cladistics. Am a bit bored 
with these kinds of debates so will say no more. 

Phil Manning: New discoveries in the Yorkshire Jurassic.

Dig at Kettleness, near Whitby, has yielded new ichthyosaur species. I 
was on this dig.. though I didn't actually do any digging. Also new 
dinosaur tracks and possible scelidosaur material.

Makoto Manabe: A 23 m ichthyosaur from the Upper Triassic of 
Canada.

Yes, 23 m. That is not a typo. First reported by an archaeologist 
looking for Amerindian burial sites and then reported to the Tyrrell, the 
specimen has not been easy to excavate and some deforestation has 
occurred. Skull is more than 5 m long with enormous supratemporal 
fossae which are floored with bone, pierced by tiny foramina. Very 
odd. There is a slight tailbend preserved but there are no wedge-shaped 
centra. Is not _Shonisaurus_, not does it seem to be a shastasaur. 
Gigantic ichthyosaurs thus evolved in the Carnian-Norian and appear 
to have died out at the end of the Triassic (but there are Liassic giants, 
not mentioned by Makoto). _Utatsusaurus_ is now known from 
Canada, suggesting biogeographical link across Panthalassian Ocean.

Still have synapsids, parareptiles and lepidosauromorphs to go. Might 
find time later on today. In view of my previous comment (about 
theropods being the new rodents), recently found the following quote. 
It was written by Robert Wilson, a prominent rodent worker, in a 
tribute volume on rodents:

"I still remember my first meeting with Richard Swann Lull when I 
came east to study Bridger rodents at the Yale Peabody Museum. I was 
ushered into his august presence by Nelda Wright, and after the usual 
exchange of pleasantries, Professor Lull volunteered that he only knew 
two things about rodents, that they all looked alike, and that they never 
changed! Dinosaurs and mice and the twin shall never meet I suppose, 
but the meek, as now based on numbers of workers, seem about to 
inherit the earth"  - - - R.W. Wilson, 1989.

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth, Environmental & Physical Sciences
UNIVERSITY OF PORTSMOUTH
Burnaby Building
Burnaby Road                           email: darren.naish@port.ac.uk
Portsmouth UK                          tel: 01703 446718
P01 3QL