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Re: pterosaur wings and scans



Jim Cunningham (jrccea@bellsouth.net) wrote:

<I'm not sure that this is the case in all pterosaurs.>

  Could you clarify for me? Much of my reasoning involves the very forward
center of gravity anatomy of the femur, which shows that unlike lizards it
was not truly capable of a good deal of lateral direction; if it tried to
walk while vertical, and its hip was vertical, it would fall. If the
animal walked bent-kneed to pull the CG closer to the ground and with the
fulcrum of the feet better separated, this will cause its gait to become
very ungainly, and the feet to turn outwards, which will force the femur
to act in a lizardlike fashion and rotate outwards on the forward step;
such a step is at odds with ankle anatomy, and will cause a vertical
animal to swing side to side, which humans solve by having joints in line
with the plane of travel, as do birds.

  I am sure that some pterosaur can solve the problem, but it seems that
essential anatomy is against this to some degree in rhamphorhynchoids and
pterodactyloids that I have looked at, to any degree.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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