Yurgovuchia doellingi, new dromaeosaurid from Utah

[Gryphoceratops]

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036790

[ZoPteryx]

Very cool!   Hmmm, increasing tail flexibility with increasing length, I wonder why that is?  I'd would have thought it would be reversed.

[Sharptooth]

Cool discovery, too bad we don't have the skull of this guy 

[DinoFan45]

Very cool!   Hmmm, increasing tail flexibility with increasing length, I wonder why that is?  I'd would have thought it would be reversed.

Maybe it was used for balance in an mountain or swamp ecosystem.

[ZoPteryx]

That's possible.  Maybe it could have also used its flexible tail to act as a rudder while running, like that of a Cheetah.