Re: new boook on functional morphology

[pharrinj@PLU.edu]

On Thu, 18 Jan 1996, Stan Friesen wrote:

> From: pharrinj@PLU.edu
>  > I BELIEVE that Johnson and Ostrom claimed that the structure of 
>  > the ceratop(s)id pectoral girdle was *inconsistent* with an erect gait 
>  > (i.e. that the bones did not fit right when put together in an upright 
>  > configuration.          
> 
> That is also my understanding of their results.
> 
> It is true that a bow-legged walking posture is consistant with
> the trackways, just barely.  But the contortions the front limb
> would have to sustain in this position make me hesitate to accept
> that conclusion.  The reason is the the toes point slightly outwards
> in the trackways. In a bow-legged position, the natural position for
> the manus would be for the toes to point *inwards* (try holding your
> elbows splayed out,  with your hands in front, and then turn your
> hand so the finger point out - OUCH).

Right.  Do you know if the forward distance between manus tracks would allow 
the arm to be bowed?  I should think that the animal would need its forelimb 
to be as long as it could make it, in order for it to keep up with those 
long hind legs!

I would imagine that if it hurts a HUMAN wrist (highly flexible) to 
put it in the bowlegged position, then the dinosaur wouldn't stand a chance.

All in all, the bowlegged ceratop smacks rather strongly to me of special 
pleading.

> 
> swf@elsegundoca.attgis.com             sarima@netcom.com > 
> The peace of God be with you.
>