[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: pterosaur tracks from SVP

At 04:47 PM 10/29/99 -0700, Martin Brazeau wrote:
>Betty Cunningham wrote:
> >Dave Unwin and Don Henderson said that they tried 3 different body
>>positions-1 bipedal and 2 quadrepedal with different body orientations,
>>and that this was the only locomotion that came out with the animal
>>stable (balanced) out of all of them AND that matched the available
>>tracks AND that matched the possible articulations of the bones.
>... I feel that the computer  
>model should have had the the head oriented behind the center of gravity, 
>something like a pelican.

Another possibility that might need consideration is the fact that living
things need not maintain a stable posture - after all, they can use muscles
to attain *dynamic* equilibrium.  A case in point is the erect bipedal
stance of _Homo sapiens_. Without muscular effort, it is unstable.

May the peace of God be with you.         sarima@ix.netcom.com