Last updated on April 21, 2014 at 11:58 EDT
Bird-like Breathing Systems in Dinos Documented Image 2
1537 of 3476

Bird-like Breathing Systems in Dinos Documented (Image 2)

July 26, 2010
The pulmonary air-sac systems of dinosaurs and birds exhibit striking similarities, including predicted regions air of sac integration into the skeleton. The air sacs act like bellows to move air through the rigid lungs.

Theories about animals' relatedness were first proposed in the late 19th century but soon fell out of favor. Evidence gathered over the past 30 years, however, has breathed new life into the hypothesis.

The work of two National Science Foundation-supported researchers makes clear the unique pulmonary system of birds, which has fixed lungs and air sacs that penetrate the skeleton, has an older history than previously realized. It also dispels the theory that predatory dinosaurs had lungs similar to living reptiles, like crocodiles.