Concise hierarchy

(Kingdom) Animalia - (Phylum) Chordata - (Class) Synapsida

Phylogeny

Paraphyletic/Ancestral (para)

Current position

†Synapsida (Class) Osborn, 1903

Ref: M.J. Benton, 2015: 437; Benton, 2015: box 5.3 (p. 133).

Alternative positions

Reptilia (Class) Linnaeus, 1758	Ref: T. Rees, 2006-present: [5 Jun 2025]; IRMNG[5 Jun 2025].
†Synapsida (Subclass) Osborn, 1903	Ref: D. Lambert & the Diagram Group, 1991(1997): 99.

Historical positions

†Unnamed (Suborder)	Ref: M.J. Benton, 2015: 437, box 5.3 (p. 133). [phylogenetic position]
†Synapsida (Class) Osborn, 1903	Ref: M.J. Benton, 2005: 394, box 5.3.
†Synapsida (Subclass) Osborn, 1903	Ref: 1998
†Synapsida (Subclass) Osborn, 1903	Ref: D. Lambert & the Diagram Group, 1991(1997): 99; 96.
†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: 623.
†Synapsida (Subclass) Osborn, 1903	Ref: A.S. Romer & T.S. Parsons, 1986: App. 1 (p. 623).
†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	†3g
1989-present	Systema Naturae 2000	[; †6so;36f]
[1995-]1996	P. Uetz: 30 Dec 1996	[; †30f]
1988	R.L. Carroll: 624	[; †49f]
1973 (1971)	B. Grzimek et al.: 591	[; †31f]