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PYTHONOMORPHA REVISITED



Sorry folks, this post is about lizards - no dinosaurs. But they're dinosaur-
contemporary lizards at least. 

Absolutely ages ago, Adam Yates informed me of Michael Lee's hypothesis where
mosasauroids were postulated to be the sister-group to snakes. The paper
presenting this has now been published...

LEE, M.S.Y. 1997. The phylogeny of varanoid lizards and the affinities of
snakes. _Phil. Trans. R. Soc. Lond. B_ 352: 53-91

Lee concludes that platynotans are monophyletic and presents 40 synapomorphies
corroborating a mosasauroid-snake clade called the Pythonomorpha - a name coined
by Cope in 1869. Pythonomorphs are the sister-group to an unnamed clade composed
of the varanids, _Cherminotus_ and _Lanthanotus_, and together they are the
Thecoglossa. _Telmasaurus_ is the sister-taxon to the Thecoglossa. Of the many
other items of interest, Lee disbands the necrosaurids as polyphyletic.

Also worthy of note here, though not relevant to this particular paper, is the
mosasauroid taxon Natantia which I have seen used in a couple of cladograms. I
think the name has already been used for a bunch of ostracod crustaceans, in
which case it can't be used for the mosasauroids. I don't doubt that Lee's
hypothesis will be much debated (much like all that turtle phylogeny work.. err,
this _is_ the same Lee isn't it?): Rieppel for one has voiced serious objections
to the idea of snakes as varanoids (some of the funny little burrowing snakes
share odd characters with amphisbaenians and scincoids).

And, on a less snaky theme, this just in..

EVANS, S.E. and BARBADILLO, J. 1997. Early Cretaceous lizards from Las Hoyas,
Spain. _Zool. Jour. Linn. Soc._ 119: 23-49

Las Hoyas yields 3 lizard taxa, and one of these, _Meyasaurus diazromerali_ sp.
nov., is described here. _Meyasaurus_ is seen here as an outgroup to the
teiioids. The specimens are pretty complete, so get hold of this paper if you
want to draw lizards running around the feet of your _Pelecanimimus_ (chuck in
an albanerpedontid too as they're cool).

Ichthyosaurs.. I hear that recent palaeobstetric work on ichthyosaurs has shown
that babies coming out head first drowned, got stuck in the cloaca, and then
killed the mum by a kind of toxic shock (OK, that term may not be applicable
here). Can someone give me a ref for this please?

"Armadillos! Smooth on the inside, crunchy on the outside! Armadillos!"

DARREN NAISH
dwn194@soton.ac.uk