\Pter`o*sau"ri*a\, n. pl. [NL.] (Paleon.)
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}.