Class [Reptilia] Linnaeus, 1758 - reptiles Subclass Lepidosauria Duméril & Bibron, 1839 Order Rhynchocephalia Günther, 1867 - tuataras Suborder Sphenodontoidea Lydekker, 1888 Family Sphenodontidae Cope, 1871 - tuataras Subfamily Sphenodontinae Cope, 1871 Genus †Clevosaurus Swinton, 1939