Concise hierarchy

(Kingdom) Animalia - (Phylum) Chordata

Phylogeny

Paraphyletic/Ancestral (para)

Ref: M.J. Benton, 2005: 394.

Current position

Synapsida (Clade) Osborn 1903 [Laurin & Reisz 2020]

Ref: M.J. Benton, 2005: 394. [implicit]

Alternative positions

Reptilia (Class) Linnaeus, 1758	Ref: T. Rees, 2006-present: [5 Jun 2025]; IRMNG[5 Jun 2025].
†Synapsida (Subclass) Osborn, 1903	Ref: R.L. Carroll, 1988: 622.
†Synapsida (Class) Osborn, 1903	Ref: M.J. Benton, 2005: 394.
Synapsida (Clade) Osborn 1903 [Gauthier et al. 1989], nom. cl. inval.	Ref: M.J. Benton, 2005: 394. [implicit]
†Theropsida (Subclass) Seeley, 1896	Ref: H.-P. Schultze et al., 1985: 2.

Historical positions

†Synapsida (Class) Osborn, 1903	Ref: M.J. Benton, 2005: 120, 394.
†Synapsida (Subclass) Osborn, 1903	Ref: 1998
†Synapsida (Subclass) Osborn, 1903	Ref: D. Lambert & the Diagram Group, 1991(1997): 96. [inferred name]
†Synapsida (Subclass) Osborn, 1903	Ref: P. Uetz, [1995-]1996: 30 Dec 1996.
†Synapsida (Subclass) Osborn, 1903	Ref: 1995
†Synapsida (Subclass) Osborn, 1903	Ref: R.L. Carroll, 1988: 622.
†Synapsida (Subclass) Osborn, 1903	Ref: A.S. Romer & T.S. Parsons, 1986: App. 1 (p. 623).
†Theropsida (Subclass) Seeley, 1896	Ref: H.-P. Schultze et al., 1985: 2, 57.
†Synapsida (Subclass) Osborn, 1903	Ref: T.I. Storer et al., 1979
†Synapsida (Subclass) Osborn, 1903	Ref: B. Grzimek et al., 1973 (1971): 590.

Number of Subtaxa

2025	Available in Systema Naturae 2000	†2g
1989-present	Systema Naturae 2000	†6f
2005	M.J. Benton: 120	†6f
[1995-]1996	P. Uetz: 30 Dec 1996	[; †8f]
1988	R.L. Carroll: 623	[; †6f]
1973 (1971)	B. Grzimek et al.: 590	[; †8f]