bild

Pterosaur ancestor, artwork. Pterosaurs were flying reptiles that lived 220-65.5 million years ago. An immediate ancestor to the pterosaur has not yet been discovered. This hypothetical animal is a small, furry, squirrel-like relative of the dinosaur, climbing up a tree. (KEYSTONE/SCIENCE PHOTO LIBRARY/MARK P. WITTON/SCIENCE PHOTO LIBRARY)