Re: Regarding Spinosaurus

[Graydon <graydon@dsl.ca>]

On Mon, Jan 07, 2002 at 03:23:51PM -0600, Williams, Tim scripsit:
> Graydon wrote:
> >Has anyone considered the possibility of the jaw structure being
> >intended, not particularly for pscivory, but for feeding from the body
> >cavities of sauropods?
> 
> You mean like vultures? 

Not particularly like vultures; I'm thinking that they were active
predators, but that they might have had an odd mode of feeding.  The
contents of the body cavity tend to the highest food value of any part
of the prey animal, and there's problems with using _all_ of a carcass;
it might make sense to specialize in getting the most nutritional value
from the kill before abandoning it, in preference to defending it.
(Since that usually isn't actually worth the effort, once you're full.)

> Spinosaurs have a strong manual claw that might have been useful in
> tearing open carcasses.  Spinosaurs would also need a flexible neck -
> and, judging from the cervical articulations, this appears to be the
> case.  If I've interpreted Graydon's post correctly, the spinosaurs
> could use their slender heads for probing through the rib cage of big,
> dead herbivores - perhaps picking out the leftovers left behind by
> stronger, more predaceous theropods.  A real nice idea.*  It might
> also explain the posteriorly-migrated nares - it can be pretty icky
> nosing around deep inside carcasses.

It does all seem to fit; anyone got a suggestion as to how one could
test it?

> *I should add that _Baryonyx_ has been found with fish remains in its
> stomach, hence the currency of the fish-eating spinosaur idea.  However,
> this only tells us what the individual's last meal was, not what the diet
> was for the entire species.

I can see them eating fish just fine, too; I doubt any theropod has ever
been what one would call a picky eater.  I do have some trouble
imagining a multi-ton terrestrial facultive fisheater, though.

-- 
graydon@dsl.ca   |  Hige sceal þe heardra, heorte þe cenre,
                 |  mod sceal þe mare þe ure maegen lytlað.
                 |   -- Beorhtwold, "The Battle of Maldon"