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RE: How did dromaeosaurs use their arms?



Matthew Bonnan writes:

>No.  Only that theropod femora, and their articulation with the acetabulum,

>do not permit the abduction/adduction motions of the hindlimb observed in 
>mammalian predators, which have a spherical femoral head.  Dinosaurs in 
>general have a stiff-action limb joint that is great in parasagittal 
>(upright posture) plane moving fore and aft, but is not very good at 
>abduction (moving the femur away from the body).  The physical articulation

>of the femoral head with the hip socket prevent abduction -- you would have

>to disarticulate the femur from the socket in order to do it.

I'm not very knowledgeable on anatomy, but if the above is true, wouldn't
developing forearms that enable you to hop, skip, jump, bound, change
direction rapidly thus risk dislocating those very hip joints you say are
the cause of the problem in the first place?

cheers, martin