Class Reptilia Linnaeus, 1758 - reptiles
   Subclass Lepidosauria Duméril & Bibron, 1839
     Order Rhynchocephalia Günther, 1867 - tuataras
       1 Suborder †Rhynchosaurida see Order Rhynchosauria Osborn, 1903
       2 Suborder †Pleurosaurida [monotypic]
       3 Suborder †Clarazidaurida
       4 Suborder Sphenodontida Carroll, 1985 [monotypic] see Order Sphenodontida Carroll, 1985