Re: Sauropods

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Mickey Mortimer" <Mickey_Mortimer111@msn.com>
Sent: Tuesday, May 21, 2002 7:12 AM

> The discovery of Rapetosaurus has pretty much
> guaranteed the placement of nemegtosaurs in the Titanosauria.

Finding *Rapetosaurus* _between_ *Nemegtosaurus* and *Quaesitosaurus* does
look somehow suspect to me, though, as it requires a very weird biogeography
for the group.

> I still don't like
> the idea that Euhelopus is a titanosaur though.

Especially considering that

Mathew [sic -- apparently correct] J. Wedel, Richard L. Cifelli & R. Kent
Sanders: Osteology, paleobiology, and relationships of the sauropod dinosaur
*Sauroposeidon*, Acta Pal. Pol. 45(4), 343 -- 388 (2000)

has shown that convergence in pneumatic features is not rare among
sauropods. *Mamenchisaurus* has at least semicamellate, probably camellate
vertebrae ( = styrofoam like *Hatzegopteryx*) like brachiosaurids and
?derived titanosaurs, while *Omeisaurus* has camerate vertebrae like a few
?basal titanosaurs, *Camarasaurus* and Diplodocidae (which have a derived
form of this, the polycamerate condition), but unlike *Haplocanthosaurus*
which has a more basal condition termed procamerate. ~:-| -- I got the pdf
(itself as big as *Sauroposeidon*) for free from
www.snomnh.ou.edu/pdf/2000/00-28.pdf, it was announced onlist a year ago or
so.