Paleontologists seek the ancestors that could explain how bats became the only flying mammals.
Listen carefully on a quiet summer night and you might hear them. Even if you don’t see a bat’s frantically fluttering form, you might catch its high-pitched chirp as it searches the night for dinner. You’re probably hearing a little brown bat, a common insect-eater found throughout North America, but it is just one of more than a thousand species of bat ranging from the one-inch-long Kitti’s hog-nosed bat to the enormous, three-pound giant golden-crowned flying fox.
Large or small, bats suffer a reputation problem. Aside from being associated with vampires, they’re often called “flying rats” and blamed for the spread of zoonotic diseases into humans (including COVID-19, though whether that blame is founded is as of yet unclear.) This fear often overshadows the fascinating fact that bats are the only mammals to have evolved powered flight, and they’ve been flapping around for tens of millions of years. Where, then, did these flying oddities come from?
Bats pop up in the fossil record around 50 million years ago during a time known as the Eocene. Paleontologists have recovered remains ranging from teeth and bits of jaw to stunning full skeletons in places as far-flung as Wyoming, Paris, Australia and India’s Vastan Mine.