evolution of theropod wrist motion

["James Norton" <jnorton@une.edu>]

If the BCF folks are correct, and theropod dinosaurs are the secondarily 
flightless descendents of early feathered flyers, wouldn't there have been 
enough evolutionary time between the earliest theropods and Deinonychus, for 
example, for theropods to have regained the wrist mobility one would expect in 
a ground-based predator?  Wouldn't the ability to rotate, pronate, supinate, 
adduct and abduct the wrist have been enough of an advantage in prey capture to 
reverse the early flight-stroke adaptations?  Why would the limited wrist 
mobility persist?

JMN