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Re: Speed in giants and cursors



----- Original Message -----
From: <GSP1954@aol.com>
Sent: Tuesday, March 05, 2002 10:34 PM
Subject: Speed in giants and cursors


> For the above reasons, the burden of proof is not upon those who argue
that
> giants can run, it is at least as upon those who argue they cannot.

While the above reasons are well-stated and refute the validity of a
comparison of theropods to elephants, this is not the crux of HP
Hutchinson's argument; the biomechanics are.  The comparison to elephants is
useful due to size, and what you have done is given good reasons to
discontinue that comparison.  However, HP Hutchinson, in both his
correspondences to the list and in the paper materials, has stressed his
biomechanical work, which has not yet been refuted.  Not only has it not
been refuted, but it has been mostly ignored by those making
anatomically-based arguments on this list.  HP Hutchinson has made a case
using biomechanics, so to refute him one must disprove his biomechanics, not
use anatomical points that he has already taken into account.

> The
> tibia/femur ratio of tyrannosaurs including T rex were similar to those of
> horses - all the are more remarkable since the theropods were so much
bigger
> - much higher than those of similar sized rhinos, and far exceed those of
> elephants. A strange pattern for animals that did not run.

Rhinos are comparable in size to Albertosaurus, not Tyrannosaurus.  Thus,
once biomechanical studies are complete for an Albertosaurus, maybe the
conclusion will be that this animal can indeed run.  But two tons are very
different from T. rex's six, or, on the low end, four.

Futhermore, quadruped-to-biped comparisons do not take into account the
extreme mechanical differences between those two locomotory types, IMHO.

Which brings me to a point that I don't understand, and that is how and why
exactly does weight not play a big part in HP Hutchinson's equations.  I
can't seem to grasp why that is, but maybe the explanation has already been
given too many times and is just over my head.

Thanks for this opportunity for an undergrad to get in the ring with big
shots!

Demetrios Vital