Clade Lepidosauria Haeckel 1866 [de Queiroz & Gauthier 2020]
see Subclass Lepidosauria Duméril & Bibron, 1839
Clade Rhynchocephalia Günther 1867 [Gauthier, Estes & de Queiroz 1988]
see Order Rhynchocephalia Günther, 1867
Clade Sphenodontia Williston 1925 [Evans 2003]
Clade Acrosphenodontia Chambi-Trowell, Martinelli, Whiteside, Romo de Vivar, Soares, Schultz, Gill, Benton & Rayfield 2021
Clade Eusphenodontia Herrera-Flores, Stubbs, Elsler & Benton 2018
Clade Neosphenodontia Herrera-Flores, Stubbs, Elsler & Benton 2018
Clade Sphenodontidae Cope 1871 [Simões, Caldwell & Pierce 2020]
see Family Sphenodontidae Cope, 1871
Clade †Eilenodontinae Rasmussen & Callison 1981 [Simões, Caldwell & Pierce 2020]
see Subfamily Eilenodontinae Rasmussen & Callison, 1981
Genus †Sphenotitan Martínez, Apaldetti, Colombi, Praderio, Fernandez, Santi Malnis, Correa, Abelin & Alcober, 2013
†Sphenotitan leyesi Martinez et al., 2013