Sphenodontia
Members: 1 genus; Sphenodon, Tuatara.
Taxonomy
Sphenodontia is an order of lizard-like reptiles that includes only one living genus, Sphenodon.
Sphenodontia was once a wastebin taxon containing a diverse array of unrelated reptiles, notably the rhynchosaurs. Today consists of three families.
Families
Gephyrosauridae, ossibly paraphyletic.
Pleurosauridae
Sphenodontidae, contains all modern tuatara