What does "pterosauria" mean?

Pterosauria: An extinct order of flying reptiles of the Mesozoic age; the pterodactyls; -- called also Pterodactyli, and Ornithosauria. Note: The wings were formed, like those of bats, by a leathery expansion of the skin, principally supported by the greatly enlarged outer or " little" fingers of the hands. The American Cretaceous pterodactyls had no teeth. See Pteranodontia, and Pterodactyl.