Alligators have one-way lungs

     A new finding shows that alligators have birdlike lungs, in which air flows in only one direction instead of in and out of chambers.  In birds, this is an adaptation to low-oxygen environments in the upper atmosphere.
     Birds and crocodiles share a common ancestor, which also gave rise to the dinosaurs.  Since it is unlikely that such a structure would evolve twice in close relatives, it seems nonbird dinosaurs also had such lungs.
     Interestingly, the alligators in the study were either under anesthesia or dead .  In other words, alligator wrestlers were too expensive to hire.

http://news.bbc.co.uk/2/hi/science/nature/8453053.stm

-Brown Rhino