Group of reptiles characterised by having two holes (temporal fenestra) in each side of their skulls. The first diapsids appeared in the late Carboniferous period. Living diapsids include all crocodiles, lizards, snakes and tuatara.- Category ID : 424163
Information from the Tree of Life Web Project on this group of reptiles which includes lizards, Sphenodon, crocodylians, birds and their extinct relatives.
Information from Wikipedia on this family of reptiles from the late Triassic, characterized by their distinctive triangular skulls which resemble the skulls of birds.