How many known species of pterodactyls were there?
The group is more properly known as the pterosaurs – pterodactyl usually only refers to one group of these flying reptiles. The pterosaurs were not dinosaurs, but flying reptiles somewhat related to dinosaurs which split off from the lineage of diapsid reptiles sometime earlier than the evolution of the dinosaur line. Likewise, birds are not direct descendants of the pterosaurs. Birds are thought to be descendants of small theropod dinosaurs or thecodont reptiles closely related to dinosaurs. The pterosaurs are a completely independent group of flying reptiles. There are a few hundred described species of pterosaurs that fall into two main groups: The earliest group, called the basal Pterosauria, or sometimes ‘rhamphorhynchoids’ are characterized by long tails, and were mostly small. The typical form was Rhamphorhynchus, which was about the size of a crow. These early pterosaurs first appeared in the Late Triassic, and disappeared by the end of the Jurassic (about the time true birds w
