Re: Diplodocus: Return to the Swamps????

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

Here's a good reconstruction of what a theropod foot looks like going into and 
coming out of mud, 
courtesy of Stephen Gatesy:

http://www.brown.edu/Administration/News_Bureau/1998-99/98-123g.html

It goes in splayed with plenty of resistance (limiting the depth of 
penetration), but is drawn out with 
converged toes that offer far less resistance. Sauropods, on the other hand, 
would have had to 
fight each step to extract a foot from deep mud. That's bound to tire a large 
animal out after a 
while.

Bipeds also had the option of walking plantigrade with their ankles flat to the 
mud, for which there 
is trackway evidence:

http://paleo.cc/paluxy/elong.htm

It would have been awkward, but would have provided even more surface area to 
prevent sinking 
in the first place.

-- 
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Dann Pigdon
GIS / Archaeologist                Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj
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