Are pterodactyls dinosaurs?

“Pterodactyl” is a common term for the pterosaur (meaning “winged lizard”) but really refers to a subgroup of pterosaurs. Pterodactyls are a staple of dinosaur movies, along with the t-rex, stegosaurus and triceratops, but they are actually flying reptiles, not dinosaurs.

Dinosaurs are descended from the common ancestor of the groups Saurischia (all carnivorous dinosaurs and some herbivores) and Ornithischia (beaked herbivores). These two groups were classified by their hip structures and had legs directly beneath their bodies (in contrast to reptiles such as lizards or crocodiles whose legs emerge from their sides). Furthermore, dinosaurs are defined as land-dwelling, and therefore do not include any marine – or flying – reptiles.

Pterosaurs lived from the late Triassic Period (230 million years ago) through the end of the Cretaceous Period (65 million years ago). They ranged in size from the tiny Nemicolopterus crypticus with a wingspan of only 10 inches, to the enormous Quetzalcoatlus northropi, whose 36-foot wingspan is the largest of any flying animal, past or present.