Pterosaurs were the denizens of the sky during the last age of the dinosaurs. They were the first animals, besides insects, to learn how to fly by flapping their wings. They were related to the dinosaurs, but not dinosaurs themselves. These giant reptiles died out during the mass extinction. During the Upper Cretaceous, the azhdarchidan species ruled the skies with wings up to 40 feet (12 meters) long. These toothless pterosaurs lived all over the world near rivers and lakes [sources Maynard].
Many of the 100-plus species of pterosaurs lived during the Cretaceous. Some were pterodactyloids, such as ornithocheiroids, which had a wingspan of about 20 feet (6 meters). Some were smaller,such as Jeholopterus, which lived during the Early Cretaceous in what is today Inner Mongolia. Jeholopterus' wingspan stretched only 35 inches (90 centimeters) [source: Pterosaur.net].