RE: T. rex as ankylosaur specialist

[Ken.Carpenter@dmns.org]

Pedal claws are not very curved, which is how foot and hand claws are
easily separated.


Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology/
Chief Preparator
Department of Earth Sciences
Denver Museum of Nature & Science
2001 Colorado Blvd.
Denver, CO 80205
 
Phone: 303-370-6392
Fax: 303-331-6492

for PDFs of some of my publications, as well as information of the Cedar
Mountain Project: 
https://scientists.dmns.org/sites/kencarpenter/default.aspx
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-----Original Message-----
From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf
Of Dann Pigdon
Sent: Wednesday, May 31, 2006 3:11 PM
To: DML
Subject: Re: T. rex as ankylosaur specialist

Tim Donovan wrote:
> 
> I don't think a tyrannosaur could flip an ankylosaur with its feet.

Lets look at the facts:

- Tyrannosaurs had some of the most gracile limb proportions of any
large theropod (maybe THE most gracile).

- Tyrannosaur legs were capable of carrying around several tonnes of
mass, so they weren't exactly weak. Most body parts tend to be
over-engineered to allow for unusual circumstances, so it's safe to
assume those legs were able to do more than (only just) carry the
animals body weight.

- Tyrannosaur pedal claws were strongly recurved.

So you have a large multi-tonne animal with long, strong legs and
recurved pedal claws. This sounds a lot like an animal that was able to
use its legs for more than just locomotion (hence my secretary bird
analogy). Considering the combined strength and usefullness of the legs
and jaws, it's no wonder they could afford to lose functionality in the
forelimbs.

Of course the big question is: would a Tyrannosaur have enough balance
and leverage to be able to topple something with such a low centre of
mass as an ankylosaur? Maybe if the tyrant avoided an ankylosaur charge
by pivotting about the hips, and could reach out quickly with one leg,
and managed to hook its pedal claws onto the moving ankylosaur, MAYBE
then it might have been able to use the prey's own momentum coupled with
a backward sweep of the leg to unbalance it. 

It would take a major feat (feet?) of agility on the part of the
theropod though...


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Dann Pigdon
GIS / Archaeologist         http://heretichides.soffiles.com
Melbourne, Australia        http://www.geocities.com/dannsdinosaurs
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