[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: T. rex the Licensed Hunter
>Let me begin by saying that I greatly respect John R. Horner, but
>with his characterization of _Tyrannosaurus rex_ as being primarily an
Agreed on both points.
>I propose a different modern analog: the 53-ton sperm
>whale! It is the largest extant predator (excluding filter-feeding
>whales, which clearly don't compare with theropods at all),
I think there's no evidence that there's *ever* been a larger predator
upon large life-forms than P. catodon (old thread turns over in grave).
But I must say I don't see any analogy between P. catodon and T. rex
>Unlike the tyrannosaurid, it is a swimming animal, but, like a
>tyrannosaurid, it has no forearms and grabs prey with huge jaws which
>studded with robust teeth (although, unlike a tyrannosaurid, the whale
>has teeth on the mandible).
I must say that I see no comparative value here. I think you're
implying that Horner's argument concerning useless forearms is weakened
by the example of P. catodon, but life in the water has it's own
entirely separate set of demands and allowances. For that matter, so
does life on land as a quadruped (many have compared T. rex's mouth-only
pursuit strategy to wolves, dogs and other predators, but T. rex was not
a quadruped and did not weigh eighty pounds).
What (terrestrial) animals have ever existed that can be analogized to
theropod dinosaurs in terms of both body configuration *and* mass? None
to my knowledge. This must make rigorous study of theropods both
frustrating and intriguing. It certainly seems to limit useful
comparisons to those within the group itself (theropod to theropod).
So I'd propose that the better question to ask is: how does T. rex
compare to other theropods? If they fairly obviously used their
forelimbs as part of their predation tactics, what does this mean about
T. rex? Does T. rex compensate in other ways to satisfy assumed
required criteria for active predation?
This leads to the next query: is Horner correct in saying that theropods
actively pursuing their prey required useful forelimbs as well as jaws
to secure and subdue prey? If so, do T. rex's unique features (if I am
correct: robustness of teeth, neck vertebrae and jaws, and length of
legs) compensate for the lack of effective grasping forelimbs?
For what it's worth, I've been convinced by the many persuasive
arguments that a jaws-alone strategy for T. rex was viable. But put a
few glasses on wine in me and I'll believe anything.
Get Your Private, Free Email at http://www.hotmail.com