Dromaeosaur tails and twisting

[David Krentz <ddkrentz@charter.net>]

  Can anyone tell me if this tail has a twist in the distal end?   
Interesting that there is a s-curve though with all those long rods  
"stiffening" the tail.  It seems as though the consensus is that the  
fossil is distorted.
Generally though, how much twist was there in dinosaur tails?  For  
instance, could the tail of a T.rex twisted so that by the end of the  
tail the vertabrate have rotated 90 degrees?  What modern lizards are  
good analogies for dinosaur tails.  Are dino tails depicted as too  
stiff?

 D