Jan. 3 (UPI) --The highly efficient breathing mechanism known as the lung-air sac system, found among early birds and dinosaurs, has long intrigued paleontologists and evolutionary biologists. But ...

Dinosaurs are far from 'extinct', but dominate as birds still most regions of the globe. Part of this huge success is due to the evolution of air sacs, which are crucial for the high efficiency of ...

"The respiratory organs of vertebrates exhibit a tremendous degree of diversity, but the lung-air sac system of birds is truly unique among extant species," says Dr. Markus Lambertz from the Institute ...