Re: gallop

["Michael Teuton MD" <tons@ccs.netside.com>]

Now this is just a question for thought, and not a challenge, but why 
would the lumbar and thoracic vertebrae cause a problem for a 
galloping dinosaur?  If the acetabulum supports the femoral head and 
the surrounding soft tissue and connective tissue keeps it there 
under load then the pelvis would be adequate for running.  That's 
assuming an adequate range of motion for the femoral head.   If the 
pelvis is adequate for birthing, supporting muscles,  allowing 
passage of other organs in and out, and supporting the abdominal 
viscera, then the shape shouldn't matter that much.   

The same applies to the shoulder girdle although it's anatomy and 
functions are somewhat different than the pelvis.  Looking at a rhino 
and triceratops, doesn't look that functionally different to me.  
What am I missing?

If the bones are built to take impact stresses, then that takes care 
of another problem.

A flexible spine may allow an animal to gallup faster, but shouldn't 
keep it from running if less flexible.  Only if it was sacralized or 
anklyosed would I see a problem.

Your thoughts?

Michael