Re: Cursorial adaptations (was T.rex and elephants)

[Chris Campbell <sankarah@ou.edu>]

Toby White wrote:
> 
> You wrote:
> >velocities. I like your idea of a brief charge. I've speculated and have
> >developed some restorations of Triceratops going bipedal for a step or two at
> >the culmination of a charge. I think most of their offensive activity was
> >directed at each other, however.
> 
> Dunno about a bipedal charge, but at least a bipedal lunge.  If the
> principal defensive tactics were hers-based, it wouldn't do to have a
> defender too far out of line.  But it still seems reasonable to have the
> beast rock back and up on his hind-legs, thus reducing his moment of
> inertia, then pivot, following the dodging tyrannosaur. At the auspicious
> moment, he lunges, perhaps aiming low to snap a tendon with those remarkably
> powerful jaws.

I think this might be a species thing; the long horn species might just
go for a stab, while the short horns might go for a bite.  That beak
looks like it could wreak some serious carnage, and anyone who's tussled
with a macaw will tell you that those beaks are something to be feared!
 
> Plausible, anyway.  I have a little trouble believing a ceratopsan could
> develop the speed, but it would't need too much.  Also, in a semi-erect
> position, he'd get a lot of mechanical advantage on the pivot, just by
> moving his head.  Is the ceratopsian neck strong enough to handle this kind
> of stress?

It seems to be designed for it, actually.  They have a ball and socket
joint for the neck and several fused vertebrae in the neck region, so
that sounds like a good combo for charging predators to me. 
Alternately, it might also argue for head butts/wrestling, but I'm still
a bit skeptical about that.

Chris