Concise hierarchy

(Kingdom) Pseudomonadati - (Phylum) Spirochaetota - (Class) Spirochaetia

Subsequent positions

Spirochaetes (Class) Cavalier-Smith 2002 nom. rej.

Ref: T. Cavalier-Smith, 2002a: tbl. 1 (p. 11). [assumed]

Current position

Spirochaetia (Class) Paster 2020

Ref: LPSN, 2020-present: [15 May 2026]; LPSN[15 May 2026].

Alternative positions

Scotobacteria (Class) Gibbons and Murray 1978 (Approved Lists 1980)	Ref: N.R. Krieg & J.G. Holt, 1984-1989
Spirochaetes (Class) "Garrity and Holt 2001" nom. nud.	Ref: G.M. Garrity et al., 2007: 543.
Spirochaetes (Class) Cavalier-Smith 2002 nom. rej.	Ref: J.P. Euzéby, 2016: [1 Sep 2017].
Spirochetes ([unranked])	Ref: E. Canale-Parola, 1982: 30.

Historical positions

Spirochaetes (Class) Cavalier-Smith 2002 nom. rej.	Ref: J.P. Euzéby, 2016: [1 Sep 2017].
Spirochaetes (Class) Cavalier-Smith 2002 nom. rej.	Ref: M.A. Ruggiero et al., 2015b: table 2 (p. 6).
Spirochaetes (Class) "Garrity and Holt 2001" nom. nud.	Ref: G.M. Garrity et al., 2007: 543.
Spirochaetes (Class) Cavalier-Smith 2002 nom. rej.	Ref: T. Cavalier-Smith, 2002a: tbl. 1 (p. 11). [new position]
Spirochaetes (Class) "Garrity and Holt 2001" nom. nud.	Ref: G.M. Garrity et al., 2001b: 24.
Spirochaetes (Class) "Garrity and Holt 2001" nom. nud.	Ref: G.M. Garrity & J.G. Holt, 2001a: 165.
Scotobacteria (Class) Gibbons and Murray 1978 (Approved Lists 1980)	Ref: N.R. Krieg & J.G. Holt, 1984-1989
Spirochetes ([unranked])	Ref: E. Canale-Parola, 1982: 30.

Number of Subtaxa

2026	Available in Systema Naturae 2000	5f;36g;85s;5ss
1989-present	Systema Naturae 2000: 15 May 2026	[5f;36g]
2016	J.P. Euzéby: [13 Sep 2017]	[2f;11g]
2007	G.M. Garrity et al.	[3f;13g;97s;5ss]
2001b	G.M. Garrity et al.: 24	[3f;13g]
2001a	G.M. Garrity & J.G. Holt: 165	[3f;13g]
2000		3f13g
1982	E. Canale-Parola	5g