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VORONA PUBLISHED



This might be too late to be new to anyone, but, what the hell...

The Upper Cret bird from Madagascar - a few of us have been aware of this one
for a while now - _Vorona_, is described in this week's _Nature_. As luck would
have it, I ran out of photocopy credits 5 minutes before I found the paper, so
I don't have a copy with me. Bummer.

_Vorona_ is important biogeographically (as are other Madagascan dinosaurs:
_Majungatholus_ [*not* a pachycephalosaur] and a titanosaur), but tells us
little or nothing with regard to bird origins - and the idea doing the rumour
circuit earlier this year is that it would. Word was that _Vorona_ was a sickle-
clawed relict, kind of a hangover from the dromaeosaur-avian link. Based as it
is on a tarsometatarsus, it's not impressive, and no mention is made in the
paper of any evidence for a sickle claw. Never mind.

In a summary report in _New Scientist_, Chiappe is quoted as saying (something
like) 'Mesozoic birds are turning out to be more diverse than we'd ever
imagined'. Respect to the man, but I'm fed up of hearing this with _every
single_ new Mesozoic bird fossil. Sheesh.. gimme a break.

Same ish of _Nature_ has the thing about ammonite reproduction, and the guy
(forget his name) suggests that - because of identical methods of carrying and
laying eggs - modern argonaut octopods are descendants of ammonites! See the
rebuttal to this in the _New Scientist_ report on it.

WRIGGLY ICHTHYOSAURS

I've also only just discovered this:

MOTANI, R., YOU H., & McGOWAN, C. 1996. Eel-like swimming in the earliest
ichthyosaurs. _Nature_ 382: 347-8

A new, complete specimen of a Lower Triassic Chinese ichthyosaur, tentatively
referred to as _Chensaurus chaoxianensis_, reveals a markedly slender trunk.
Partial skin impressions show small caudal fin. Morphology shows anguilliform
(=undulatory) method of swimming, and in a graph quantifying fineness ratio
(precaudal length/body height) and tail H/L, _Chensaurus_ clusters with the
scyliorhinid sharks. Loads more stuff about evolution of swimming and body shape
in ichthyosaurs in this paper, too much to go into here.

And this..  [I already described the following, but what the heck
             (pardon my French |-); it was a while ago. -- MR]

NORELL, M.A. & CLARK, J.M. 1996. Dinosaurs and their youth. _Science_ 273: opps,
lost the page number.

They criticise the Geist and Jones article that erroneously presented anti-
data for nesting in dinosaurs, basically saying that crocodile nesting is not
analogous to the method used by both birds and _Oviraptor_.

The reply...

GEIST, N.R. & JONES, T.D. _Science_ 273: next couple of pages.

They say that, well, crocodiles can't be the same as either dinosaurs or birds,
can they, as they only got stubby little legs, and 'We merely point out that
_Oviraptor_ fossils present no significant evidence that precludes their
reproductive biology from having resembled that of modern crocodilians'. 

That'll do.

DARREN NAISH