A pterodactyl is a type of prehistoric flying reptile classified under the order Pterosauria. Often incorrectly described as a dinosaur, pterodactyls are more closely related to modern birds and crocodiles. They lived during the Late Cretaceous period and are characterized by their wings, which were formed by a membrane of skin and muscle stretched between an elongated fourth finger and their bodies. The name "pterodactyl" typically refers to members of the genus Pterodactylus, which had a long neck and a beak filled with sharp teeth. These creatures were unique among flying animals of their time.