Concise hierarchy

(Kingdom) Animalia - (Phylum) Chordata - (Class) Reptilia - (Order) Rhynchocephalia - (Family) Sphenodontidae

Included, by definition, in node-based clade

Lepidosauria (Clade) Haeckel 1866 [Gauthier, Estes & de Queiroz 1988], nom. cl. inval.		Ref: J. Gauthier et al., 1988a: 34.
Lepidosauromorpha (Clade) Benton 1983 [Benton 1985]		Ref: M. Laurin, 1991: 89.

Included, by definition, in branch-based clade

Lepidosauriformes (Clade) Gauthier, Estes & de Queiroz 1988		Ref: J. Gauthier et al., 1988a: 28.
Lepidosauromorpha (Clade) Benton 1983 [Benton 1985]		Ref: J. Gauthier et al., 1988a: 27.

Excluded, by definition, from branch-based clade

†Clevosauridae (Clade) Fraser 1993 [Bonaparte & Sues 2006]

Ref: D.G. DeMar Jr. et al., 2022: 47 (Hsiou et al., 2015: 4).

Current position

Sphenodontinae (Subfamily) Cope, 1871

Ref: O. Kuhn, 1969

Alternative positions

Lepidosauria (Clade) Haeckel 1866 [Gauthier, Estes & de Queiroz 1988], nom. cl. inval.	Ref: T. Rowe, 1988: fig. 1.
Sphenodontidae (Family) Cope, 1871	Ref: W.E. Duellman, 1982: 958 [Reynoso, 1996: fig. 9].
Sphenodontinae (Clade) Huxley 1887 [Reynoso 1996]	Ref: D.G. DeMar Jr. et al., 2022: fig. 26. [inferred]

Historical positions

Sphenodontidae (Clade) Cope 1871 [Simões, Caldwell & Pierce 2020]	Ref: D.G. DeMar Jr. et al., 2022: 47, figs. 24A, 26.
Lepidosauria (Clade) Haeckel 1866 [Gauthier, Estes & de Queiroz 1988], nom. cl. inval.	Ref: N. Iwabe et al., 2005: fig. 1c.
Lepidosauria (Clade) Haeckel 1866 [Gauthier, Estes & de Queiroz 1988], nom. cl. inval.	Ref: T. Rowe, 1988: fig. 1.
Chordata (Phylum) Bateson, 1885	Ref: L. Margulis & K.V. Schwartz, 1982: 239. [rough position]
Sphenodontidae (Family) Cope, 1871	Ref: W.E. Duellman, 1982: 958.
Rhynchocephalia (Order) Günther, 1867	Ref: T.I. Storer et al., 1979
Sphenodontidae (Family) Cope, 1871	Ref: B. Grzimek et al., 1973 (1971): 598.
Sphenodontinae (Subfamily) Cope, 1871	Ref: O. Kuhn, 1969

Number of Subtaxa

2025	Available in Systema Naturae 2000	1s
1989-present	Systema Naturae 2000: 31 Jan 2017	[1s]
2016	P. Uetz et al.: 16 Aug 2016	[1s]
[1995-]2000	P. Uetz	2s
1982	W.E. Duellman: 958	1s
1979	T.I. Storer et al.	1s