Re: So-called Sickle Claws

["Peter Von Sholly" <vonrex@gte.net>]

I disagree.  I believe there was a large "heel pad" under the distal ends
of the 3 metatarsals and that all three toes bent forward from there, with
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.  I
think one can easily get the wrong idea by looking only at the bones and
foregetting what the soft tissues would do and the space they would fill.  
And what about the animal's ability to walk, run and balance?  You don't
think that would be compromised by the need to walk only on its two outer
toes?  To me it creates an unrealistically awakward , compromised creature.
Also, absence of evidence may indeed not be evidence of absence, but where
are the two-toed footprints, after all?
> From: NJPharris@aol.com
> To: vonrex@gte.net; dinosaur@usc.edu
> Subject: Re: So-called Sickle Claws
> Date: Saturday, August 23, 1997 11:44 PM
> 
> In a message dated 97-08-21 15:48:54 EDT, vonrex@gte.net (Peter Von
Sholly)
> writes:
> 
> > Can you imagine an animal with three big
> >  toes walking on only two?  Ot jumping with their full body weight on
big
> >  prey and hanging there on only two out of six toes?
> 
> If the inner toe is as short as it is in dromaeosaurids (due to reduction
in
> length of both the metatarsal and the phalanges), then I have no trouble
> imagining this at all.  In fact, since metatarsal II is shorter than the
> outer two mets (which are subequal in length), it would have been
> *impossible* for the animal to put the base of digit II on the ground
unless
> it was standing absolutely flat-footed.  
> 
> How much support would it get from just the tip of a claw?
> 
> A modified ligament could easily hold digit II off the ground with no
> expenditure of muscular effort and no compromise to the effectiveness of
the
> leg muscles.
> 
> NP