Compare and contrast members of order squamata with members of order sphenodonta

Sphenodontia

least specialized of all living reptiles arose in the Mesozoic era include tuataras; several unique features of the skull and jaws clearly define them and distinguish the group from the squamates

Squamata:

Most specialized reptiles. arose in the late Permian include lizards and snakes largest extant clade of reptiles