An analysis of the first three-dimensionally preserved skulls and skeletons of the extinct legged snake Najash rionegrina shows that nearly 100 million years ago (Cretaceous period), legged snakes still had a cheekbone — also known as a jugal bone — that has all but disappeared in their modern descendants, and that snakes possessed hind legs during the first 70 million years of their evolution. Najash rionegrina. Image credit: Raúl O....