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WALRUS WHALES, PLETHODONTIDS etc



Have just spent the day playing with the type specimen of 
_Neovenator_ at Dinosaur Isle Visitor Centre, Isle of Wight. 
I would like to see the full description of this specimen 
(produced by Steve Hutt in 1999) published - it will 
definitely help flesh out some details of the allosauroid tree 
- but this may take some time. The pathologies seen on the 
specimen (and on the _Iguanodon atherfieldensis_ found 
with it) are absolutely incredible, more on this soon.

For those who haven't visited, Dinosaur Isle has a life-sized 
model of _Eotyrannus_, one of the Dorling Kindersley 
caudipterid models, the world's only mounted skeleton of 
_Neovenator_ and MIWG.7306, the huge 
_Sauroposeidon_-like cervical vertebra I have been working 
on (with Dave Martill and Dave Cooper). They are also 
prepping our Oxford Clay pliosaur skull (weren't not sure 
yet if it's _Liopleurodon_ or _Simolestes_). To be honest, 
the museum doesn't have as much stuff to see as it might 
but is still worth a visit.

Tom wrote...

> de MUIZON, C. & D.P. DOMNING. 2002. The anatomy of _Odobenocetops_
> (Delphinoidea, Mammalia), the walrus-like dolphin from the Pliocene of
> Peru and its palaeobiological implications. Zoological Journal of the
> Linnean Society 134: 423-452.
> 
> This is the infamous "whalerus": a cetacean convergent on walrus
> morphology: downward pointing tusks, for instance.  A new species, _O.
> leptodon_, is named.

Well, no, it was actually named in a _Comptes Rendu_ 
paper in 1999 (_CR des Sceances de l'Academie des 
Sciences, Series II_ 303, 1401-1404): the new paper is the 
complete description. To fans of odontocete evolution, _O. 
leptodon_ is shown to be further significant in that (unlike 
_O. peruvianus_) it still had a small melon. 
Correspondingly, it apparently had less well developed 
binocular vision than _O. peruvianus_.

Also of interest in the same issue of ZJLS are....

Deban, S. M. & Marks, S. B. 2002. Metamorphosis and 
evolution of feeding behaviour in salamanders of the family 
Plethodontidae. _ZJLS_ 134, 375-400.

Documents in detail the transition plethodontids undergo 
from suction-feeding, narrow-gaping larvae to prehensile-
tongued, wide-gaping adults. These two feeding styles 
require conflicting morphological apparatus: various 
solutions have been evolved to get round this. One way is to 
delete the larval stage altogether, another is to have 
neotenous adults that suction feed like ancestral larvae. 
Needless to say this is a massive over simplification.

Georges, A., Adams, M. & McCord, W. 2002. 
Electrophoretic delineation of species boundaries within the 
genus _Chelodina_ (Testudines: Chelidae) of Australia, 
New Guinea and Indonesia. _ZJLS_ 134, 401-422.

'Nuff said.

Darren Naish
School of Earth & Environmental Sciences
University of Portsmouth
Burnaby Building
Burnaby Road                           email: 
darren.naish@port.ac.uk
Portsmouth UK                          tel: 023 92846045                   
PO1 3QL                                www.palaeobiology.co.uk