RE: Regarding Spinosaurus

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

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?  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.

There is an alternative strategy for when the scavenger is confronted with a
particularly thick-skinned carcasses.  The jaws and talons of certain
vulture species are actually too weak to rip open the hides of large
carcasses - no mean feat considering how tough the skin of an ungulate is.
So these vultures plunge their head and necks in through the gullet or the
rectum of the carcass, and gobble up the good stuff inside.  Perhaps
spinosaurs fed in a similar fashion.  (For you paleoartists out there, this
would make a simply wonderful illustration!)

*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.



Tim