Every breath you take is an ancient inheritance. The rise and fall of your chest, the intercostal muscles pulling your ribs outward, the rush of air into your lungs—this mechanism is so familiar it barely registers as remarkable. But a tiny, mummified reptile that died in an Oklahoma cave roughly 289 million years ago has revealed the oldest example of this breathing system in amniotes—a group that includes all reptiles, birds, mammals, and their common ancestors, among the first to conquer life on land.
