Alligators breathe like birds, with a one-way tube that flows all the way through their respiratory systems. While that might not seem earth-shattering at first, alligators and birds diverged 246 million years ago. And according to a new study in Science, that means this breathing technique goes way, way back, and could even explain how the ancestors of dinosaurs survived the great Permian-Triassic extinction.
Unlike a mammal’s breath, which exits the lungs from the same dead-end chambers it enters, a bird’s breath takes a loopy one-way street through its lungs [Science News]
. This breathing technique allows birds to explore high altitudes where oxygen levels drop off significantly. If the archosaurs—ancestors to birds and alligators—breathed this way, it could have given them an advantage when oxygen level tanked 250 million years ago and lots of species died off.
Before the extinction, synapsids, the ancestors to modern mammals, were the dominant ...
