The Pterosauria or Pterodactyls formed a group of flying reptiles that evolved during the Triassic period, soon after they where distributed worldwide. Pterosaurs were the first vertebrates that concoured the air. Pterosaurs (Greek for "wing lizards" ptero = winged, sauros = lizard) ruled the skies during the Jurassic and Cretaceous periods, ranging from the size of a sparrow to the largest vertebrate ever known to fly, the late Cretaceous Quetzalcoatlus, this animal named after an Aztec god, had a wingspan of twelve meter .
The evolution of there flight was separate from the flight in birds and bats, in fact pterosaurs are not closely related to either one of those groups, the evolution of flight in pterosaurs provide us with a classic example of convergent evolution.
Pterosaurs had hollow bones, large brains with well-developed optic lobes, and several crests on their bones to which flight muscles attached. All of this is consistent with powered flapping flight.
An mazingly elongated fourth digit in the hand provided the wings main support and fibers in the wing membrane gave structural stiffness and support. Some pterosaurs had a hair-like body covering, indicating a possible endothermic lifestyle,
Among pterosaurs a diverse range of head types is known, the advandtage of flight allowed them to evolve into many niches, taking advantage of many different food sources, which would explain the range of skull morphology seen.