Re: Muddy feet, or not?

[Dann Pigdon <dannj@alphalink.com.au>]

Roger A. Stephenson wrote:
> 
> Hello all,
> 
> Since there are so few trackways or track as the case may be, of
> Tyrannosaurids, in the USA can we infer anything from teh meager evidence?
> 
> Could it be they didn't like walking on slippery mud, and possible falls,(
> no joke this time)?
> 
> Could it be there was no surprise advantage in being on on a lakeshore in
> the open and weighing 6 tons, and being he most powerful predator around.
> 
> The chase would be futile on the mud flat, unless the Tyrannosaurid got lucky.
> 
> Sorry if it's been done.
> 
> Roger A. Stephenson
> Hell Creek Homey

Australia seems the land of dinosaur footprints (a few bones now and
then wouldn't hurt though). Theropod tracks 71cm long are known
from Jurassic coal deposits. Not tyrannosaurs obviously (wrong time,
wrong hemisphere), but certainly  in the right size range. 
Megalosauropus tracks up to 56cm long are known (a 9-10 metre beast
perhaps). Given the rarity of large carnivores in any warm-blooded
(assumption made) ecosystem I wouldn't hold your breath waiting for
tyrannosaur prints to be found.

Besides, I'm not convinced that tyrannosaurs chased their prey for
any great distance. Short ambushing sprints maybe. I would think that
theropods, with their wide spreading toes, would do better in the mud
than the stubby-toed large ornithopods, of which far more prints
are known (as you would expect with an endothermic predator-prey
ratio). Therefore the large ornithopods would have been at a slight
disadvantage when it came to running in the mud (not that many prints
ever show dinosaurs actually running - Lark Quarry excepted perhaps).
-- 
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        Dann Pigdon
        Melbourne, Australia

        Dinosaur Reconstructions:
        http://www.geocities.com/capecanaveral/4459/
        Australian Dinosaurs:
        http://www.alphalink.com.au/~dannj
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