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Re: So-called Sickle Claws

To my mind, it all depends on the pads on the bottom of the foot as to what
the stance would have been like.  Again, ostriches only have two toes.

> From: Dann Pigdon <dannj@alphalink.com.au>
> To: dinosaur@usc.edu
> Subject: Re: So-called Sickle Claws
> Date: Monday, August 25, 1997 3:26 PM
> Peter Von Sholly wrote:
> > 
> > I disagree.  I believe there was a large "heel pad" under the distal
> > of the 3 metatarsals and that all three toes bent forward from there,
> > pads of their own, especially under the claw of digit 2, the so-called
> > killer claw.  There is plenty of room for that toe to reach the ground.
> > think one can easily get the wrong idea by looking only at the bones
> > foregetting what the soft tissues would do and the space they would
> > And what about the animal's ability to walk, run and balance?  You
> > think that would be compromised by the need to walk only on its two
> > toes?  To me it creates an unrealistically awakward , compromised
> > Also, absence of evidence may indeed not be evidence of absence, but
> > are the two-toed footprints, after all?
> > 
> Ostriches cope quite well with only two toes per foot. I think the
> closest modern analogy for dromaeosaurs would probably be the
> cassowarie. It has a modified inner toe claw that is quite distinct
> in shape from the others. It is shaped like a long bladed carving
> knife, and it uses this as a weapon to defend itself, its young,
> or its territory. However the claw is still straight and the toe
> bears weight like the other two. I would expect that if dromaesaur
> inner foot claws also bore as much weight as the other two load
> bearing ones it would probably have been straighter that it was.
> To suggest that such a large curved claw was part of a toe that
> bore as much weight as the others to me suggests a creature that
> would have been even more disabled that one that had only two
> fully load bearing toes.
> -- 
> ____________________________________________________
>       Dann Pigdon
>       Melbourne, Australia
>       http://www.geocities.com/capecanaveral/4459/
> ____________________________________________________