Pterosaurs included the largest flying animals ever to have lived. They are a clade of prehistoric archosaurian reptiles closely related to dinosaurs. Species among pterosaurs occupied several types of environments, which ranged from aquatic to forested. Below are the lists that comprise the smallest and the largest pterosaurs known.

Smallest pterosaurs

The smallest known pterosaur is Nemicolopterus with a wingspan of about 25 cm. The specimen found may be a juvenile or a subadult, however, and adults may have been larger. Anurognathus is another small pterosaur, with a wingspan of 35 cm and 40 g in body mass, along with an indeterminate non-pterodactyloid pterosaur from the Portland Formation, although it is indeterminate and known from very fragmentary remains, only including a tooth, and part of the wrist bones.

Pterosaurs with largest wingspan

This is a list of pterosaurs with estimated maximum wingspan of more than 5 meters (16 feet): The largest of non-pterodactyloid pterosaurs as well as the largest Jurassic pterosaur was Dearc, with an estimated wingspan between 2.2 m and 3.8 m. Only a fragmentary rhamphorhynchid specimen from Germany could be larger (184 % the size of the biggest Rhamphorhynchus). Other huge non-pterodactyloid pterosaurs are Sericipterus, Campylognathoides and Harpactognathus, with the wingspan of 1.73 m, 1.75 m, and 2.5 m, respectively. Middle Jurassic Angustinaripterus had a wingspan of 1.6 m.

Speculation about pterosaur size and flight

Some species of pterosaurs grew to very large sizes and this has implications for their capacity for flight. Many pterosaurs were small but the largest had wingspans which exceeded 9 m. The largest of these are estimated to have weighed 250 kg. For comparison, the wandering albatross has the largest wingspan of living birds at up to 3.5 m but usually weighs less than 12 kg. This indicates that the largest pterosaurs may have had higher wing loadings than modern birds (depending on wing profile) and this has implications for the manner in which pterosaur flight might differ from that of modern birds. Factors such as the warmer climate of the Mesozoic or higher levels of atmospheric oxygen have been proposed but it is now generally agreed that even the largest pterosaurs could have flown in today's skies. Partly, this is due to the presence of air sacs in their wing membranes, and that pterosaurs launched into flight using their front limbs in a quadrupedal stance similar to that of modern bats, a method faster and less energy taxing than the bipedal launching of modern birds.