Pterosaurs

Pterosaurs Temporal range: Late Triassic–Late Cretaceous, 228–66 Ma PreЄ Є O S D C P T J K Pg N
Replica Geosternbergia sternbergi skeletons, female (left) and male (right)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Ornithodira
Clade:	†Pterosauromorpha Padian, 1997
Order:	†Pterosauria Kaup, 1834
Subgroups
†Eopterosauria †Macronychoptera †Dimorphodontia †Novialoidea
Distribution of pterosaur fossil locations. Colored species or genera names correspond to their taxonomic group. Adapted from Witton (2013). Taxonomic groups based on Unwin et al. (2010).

Pterosaurs (/ˈtɛrəˌsɔːr, ˈtɛroʊ-/; meaning "winged lizard") are flying reptiles of the extinct clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger. Early species had long, fully toothed jaws and long tails, while later forms had a highly reduced tail, and some lacked teeth. Many sported furry coats made up of hair-like filaments known as pycnofibers, which covered their bodies and parts of their wings. Pterosaurs spanned a wide range of adult sizes, from the very small anurognathids to the largest known flying creatures of all time, including Quetzalcoatlus and Hatzegopteryx.

Pterosaurs are often referred to in the popular media and by the general public as "flying dinosaurs", but this is scientifically incorrect. The term "dinosaur" is restricted to just those reptiles descended from the last common ancestor of the groups Saurischia and Ornithischia (clade Dinosauria, which includes birds), and current scientific consensus is that this group excludes the pterosaurs, as well as the various groups of extinct marine reptiles, such as ichthyosaurs, plesiosaurs, and mosasaurs. Like the dinosaurs, and unlike these other reptiles, pterosaurs are more closely related to birds than to crocodiles or any other living reptile. Pterosaurs are also colloquially referred to as pterodactyls, particularly in fiction and by journalists. Technically, "Pterodactyl" refers only to members of the genus Pterodactylus, and more broadly to members of the suborder Pterodactyloidea of the pterosaurs.