Re: Titanosaur Reconstruction

["T. Mike Keesey" <tmk@dinosauricon.com>]

On Wed, 1 Aug 2001, Richard W Travsky wrote:

[skull of _Rapetosaurus_]
> It settled, she said, the argument over whether these animals had a
> slender-snouted, horsey look with nostrils on top of the head and small
> teeth positioned to the front of the jaw; or rather a bulldog-shaped head
> with nostrils on the side.
>
> Rapetosaurus krausei shows the former to be the case.

So, it would appear that the "horsey"-type skull evolved twice from the
"boxy"-type skull? (Mental note: find better terms for sauropod skull
types....)

--+--Jobaria (boxy)
  `--+--Diplodocimorpha (horsey)
     `--+--Camarasaurus (boxy)
        `--+--Brachiosauridae (boxy)
           `--Titanosauria (horsey)

Interesting to note that most Cretaceous sauropods (titanosaurs and
dicraeosaurid and rebbachisaurid diplodocimorphs) had "horsey" skulls,
then. (_Jobaria_ is the only exception that comes to mind.) Could this
have something to do with a global change in vegetation? Or is this
observation flawed?

_____________________________________________________________________________
T. MICHAEL KEESEY
 Home Page               <http://dinosauricon.com/keesey>
  The Dinosauricon        <http://dinosauricon.com>
   personal                <keesey@bigfoot.com> --> <tmk@dinosauricon.com>
    Dinosauricon-related    <dinosaur@dinosauricon.com>
     AOL Instant Messenger   <Ric Blayze>
      ICQ                     <77314901>
       Yahoo! Messenger        <Mighty Odinn>