Adaptations

Pterosaurs shared a number of morphological similarities with reptiles and as such are classified as reptiles. However snakes, crocodiles, turtles, and lizards aren't capable of active flight (a few reptiles are able to achieve passive flight). So obviously there must have been major modifications to the morphology of Pterosaurs in order to achieve flight.

1) Morphological Modifications

a) The wing
b) Lightening the skeleton
c) Other skeletal elements

2) Pterosaur Skulls

a) The Skull
b) Skull Ornamentation
c) The Jaws