Re: Sauropod Biology

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

----- Original Message -----
From: "Sim Koning" <simkoning@msn.com>
Sent: Friday, January 27, 2006 4:48 PM

> I think to get a general idea on sauropod lifestyle, we should NOT look at 
> giraffes, or elephants or anything mammalian for that matter. The animals 
> that should be compared with sauropods are their ancestors, the 
> prosauropods. Consider Plateosaurus, this animal was not a high browser or 
> a low browser, it was both. This animal was the first dinosaur to graze 
> from *trees* high above the ground. It reared up onto its hind legs and 
> used its large thumb claws to pull down branches, not unlike later 
> therizinosaurs or giant ground sloths. The long neck was clearly an 
> adaptation for high browsing from trees while in a *tripodal* position.

Which adaptations for a tripodal stance can you find in *Plateosaurus*?

> This was likely the key to sauropod success,
> the fact that they were able to feed from the ground equally as well as 
> they
> could feed from the tree tops. Sauropods were probably generalist 
> herbivores
> that could feed from any level.

This does not explain why there sometimes were so many different species in 
the same place at (it appears) the same time.

> There were probably specialist sauropods such as Brachiosaurus and
> Dicraeosaurus. With its high shoulders, Brachiosaurus was likely a high
> browser like giraffes and Indricotherium, while Dicraeosaurus, with its
> *short* neck, was a specialist low browser. As with all specialists, these
> forms were prone to extinction, which is probably why the Brachiosaurs 
> died
> out not long after the Jurassic.

Well... *Sauroposeidon*, which was bigger rather than smaller than 
*Brachiosaurus*, is... how old? Aptian? That would be, like, 120 Ma... 
that's 25 Ma after the end of the Jurassic... Dicraeosaurids 
(*Amargasaurus*) and rebbachisaurids survived for a similar length of time.