Dec. 11, 2013 — Air flows mostly in a one-way loop through the lungs of monitor lizards -- a breathing method shared by birds, alligators and presumably dinosaurs, according to a new University of Utah study.
The findings -- published online Dec. 11 in the journal Nature -- raise the possibility this breathing pattern originated 270 million years ago, about 20 million years earlier than previously believed and 100 million years before the first birds. Why remains a mystery.
"It appears to be much more common and ancient than anyone thought," says C.G. Farmer, the study's senior author and an associate professor of biology at the University of Utah. "It has been thought to be important for enabling birds to support strenuous activity, such as flight. We now know it's not unique to birds. It shows our previous notions about the function of these one-way patterns of airflow are inadequate. They are found in animals besides those with fast metabolisms."
