Iguanas could breathe in one-direction like Birds

It was assumed by the Biologists that the one-way air flow was a special adaptation found only in birds, as they need high energy for flying. Whether birds are breathing in or out, air flows in a one-directional loop through their lungs. This pattern was unexpected and for decades biologists assumed it was unique to birds. But now scientists have found that birds like breathing have also developed in green iguanas. Green Iguanas are reptiles which are not known for high-capacity aerobic fitness. The finding says that the case of unidirectional bird-like flow evolved long before the first bird, which aroused nearly 300 million years ago in a common ancestor of lizards, snakes, crocodiles and dinosaurs including birds.