ADRIOSAURUS, POLYCOTYLIDS

[darren.naish@port.ac.uk]

The most recent issues of _Journal of Paleontology_ have consistently 
included good Mesozoic vert palaeo papers - they tend not to get 
reported here, don't know why. Last issue included the new Bavarian 
Jurassic ophthalmosaurian ichthyosaur _Aegirosaurus_. Current issue 
has - - 

Sato, T. and Storrs, G.W. 2000. An early polycotylid plesiosaur 
(Reptilia: Sauropterygia) from the Cretaceous of Hokkaido, Japan. 
_JP_ 74: 907-914.

This is the same specimen as the one described in _Nature_ last year 
(with stomach contents). Is a diminutive adult - biogeography and 
temporal occurrences of polycotylids are discussed and there is a brief 
review of recent phylogenies ( incl. comments on O'Keefe's 
Euplesiosauria).

Lee, M.S.Y. and Caldwellm M.W. 2000. _Adriosaurus_ and the 
affinities of mosasaurs, dolichosaurs and snakes. _JP_ 74: 915-937.

Another paper in the long-running and fascinating series of exchanges 
between these authors and colleagues and Rieppel and Zaher - 
extensive discussion of characters and phylogenies and the part the 
snake-like _Adriosaurus_ plays in all this plus a rebuttal towards Zaher 
and Rieppel's papers from '99. Rebuttal as well of the Underwood-
Rieppel idea about a burrowing ancestry for snakes. 
_Aphanizocnemus_ is supported as a member of the dolichosaurid-
snake clade. 

Berman, D.S. 2000. Origin and early evolution of the amniote occiput. 
_JP_ 74: 938-956.

The amniote occiput seems to have gone through a series of grades of 
transformation - this paper compliments other work by Sumida and 
Laurin. Diadectomorphs and synapsids form a clade - this is 
problematical in view of most people's acceptance of an Amniota that 
has diadectomorphs as an outgroup, but Lee, Spencer and Berman have 
found it in analyses before. Seymouriamorphs, temnospondyls and 
lepospondyls also form a clade. Sigh... I was so fond of the 
Reptiliomorpha:)

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