Mummified reptiles are revealing how breathing evolved

Apr 8th 2026|3 min read

ALL ANIMALS breathe in oxygen and exhale carbon dioxide, but how exactly they do so differs widely. Fish, for example, take oxygen-rich water in through their mouths before pumping it past their gill tissues, where the gas exchange takes place. Amphibians perform a similar trick, using their cheeks to push water or air to their lungs. The reptiles and mammals that descend from them, however, use muscles associated with their ribs and shoulders to contract and expand the chest cavity, drawing in and expelling air accordingly.