Re: Spinosaurs as what?

[Tim Williams <twilliams_alpha@hotmail.com>]

T. Michael Keesey wrote:

> _Ouranosaurus_ was already mentioned, and _Rebbachisaurus_ had long
> vertebral spines as well: three dinosaurs from distinct lineages
> (_Spinosaurus_ a theropod, _Ouranosaurus_ and ornithischian,
> _Rebbachisaurus_ a sauropodomorph) with the same trait, all living at
> the same time and in the same place. Coincidence? Not likely. And I'm
> pretty sure _Ouranosaurus_ and _Rebbachisaurus_ weren't living on
> fish....

That's pretty much what I was driving at.  (And I had forgotten that 
_Rebbachisaurus_ had long spines too - thanks for the reminder.)  
_Amargasaurus_ of South America may also have had a sail - or rather two 
sails.

Jura <pristichampsus@yahoo.com> wrote:

> IMHO _Suchomimus_ was the only spinosaur that seemed
> to have a jaw developed for a strictly piscivorous
> diet (not that we're exactly tripping over spinosaur
> skulls here).

I'm not so sure even _Suchomimus_ was a dedicated piscivore.  Its skull is 
very similar to that of _Baryonyx_.  The two species are very similar, and 
some researchers have even proposed that _Suchomimus_ is actually species of 
_Baryonyx_.  It all depends upon how finely-calibrated your genericometer 
is.  :-)



Tim