Concise hierarchy

(Kingdom) Pseudomonadati - (Phylum) Chlamydiota - (Class) Chlamydiia

Current position

Chlamydiia (Class) Horn 2016

Ref: LPSN, 2020-present: [13 Apr 2026]; LPSN[13 Apr 2026].

Alternative positions

Chlamydiae (Class) "Cavalier-Smith 1998" nom. nud.	Ref: G.M. Garrity et al., 2007: 541.
Chlamydiae (Class) Cavalier-Smith 2002 nom. rej.	Ref: T. Cavalier-Smith, 2002a: tbl. 1 (p. 11); Euzéby[31 Aug 2017]. [new position]
Rickettsias ([unranked])	Ref: L.A. Page, 1982: 41.
Scotobacteria (Class) Gibbons and Murray 1978 (Approved Lists 1980)	Ref: N.R. Krieg & J.G. Holt, 1984-1989

Historical positions

Chlamydiae (Class) Cavalier-Smith 2002 nom. rej.	Ref: J.P. Euzéby, 2016: [31 Aug 2017].
Chlamydiae (Class) Cavalier-Smith 2002 nom. rej.	Ref: M.A. Ruggiero et al., 2015b: table 2 (p. 3).
Chlamydiae (Class) "Cavalier-Smith 1998" nom. nud.	Ref: G.M. Garrity et al., 2007: 541.
Chlamydiae (Class) Cavalier-Smith 2002 nom. rej.	Ref: T. Cavalier-Smith, 2002a: tbl. 1 (p. 11). [new position]
Chlamydiae (Class) "Cavalier-Smith 1998" nom. nud.	Ref: G.M. Garrity et al., 2001b: 24.
Chlamydiae (Class) "Cavalier-Smith 1998" 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
Rickettsias ([unranked])	Ref: L.A. Page, 1982: 41.

Number of Subtaxa

2026	Available in Systema Naturae 2000	9f;27g;11s
1989-present	Systema Naturae 2000: 14 Apr 2026	[9f;27g]
2016	J.P. Euzéby: [8 Sep 2017]	[4f;6g]
2007	G.M. Garrity et al.	[4g;7g;14s]
2001b	G.M. Garrity et al.: 24	[4f;5g]
2001a	G.M. Garrity & J.G. Holt: 165	[4f;5g]
2000		4f5g
1982	L.A. Page	1g2s