Concise hierarchy

(Kingdom) Methanobacteriati - (Phylum) Methanobacteriota - (Class) Thermococci

Subsequent positions

Thermococci (Class) Zillig and Reysenbach 2001 nom. inval.

Ref: W. Zillig & A.-L. Reysenbach, 2001: 341. [assumed]

Current position

Thermococci (Class) Zillig and Reysenbach 2002

Ref: LPSN, 2020-present: [21 Nov 2025]; LPSN[21 Nov 2025].

Alternative positions

Euryarchaeota (Kingdom) Woese et al. 1990
Eurytherma (Infraphylum) Cavalier-Smith 1998	Ref: T. Cavalier-Smith, 1998: 219.
Protoarchaea (Class) Cavalier-Smith 2002 nom. rej.	Ref: T. Cavalier-Smith, 2002a: tbl. 1 (p. 14). [new position]
Thermococci (Class) Zillig and Reysenbach 2001 nom. inval.	Ref: W. Zillig & A.-L. Reysenbach, 2001: 341. [new position]

Historical positions

Thermococci (Class) Zillig and Reysenbach 2002	Ref: J.P. Euzéby, 2016: [31 Aug 2017].
Thermococci (Class) Zillig and Reysenbach 2002	Ref: M.A. Ruggiero et al., 2015b: table 2 (p. 2).
Thermococci (Class) Zillig and Reysenbach 2002	Ref: G.M. Garrity et al., 2007: 29.
Protoarchaea (Class) Cavalier-Smith 2002 nom. rej.	Ref: T. Cavalier-Smith, 2002a: tbl. 1 (p. 14). [new position]
Thermococci (Class) Zillig and Reysenbach 2001 nom. inval.	Ref: G.M. Garrity et al., 2001b: 3. [new position]
Thermococci (Class) Zillig and Reysenbach 2001 nom. inval.	Ref: W. Zillig & A.-L. Reysenbach, 2001: 341; xv. [new position]
Thermococci (Class) Zillig and Reysenbach 2001 nom. inval.	Ref: G.M. Garrity & J.G. Holt, 2001a: [156]. [new position]
Eurytherma (Infraphylum) Cavalier-Smith 1998	Ref: T. Cavalier-Smith, 1998: table 2 (p. 219).

Number of Subtaxa

2026	Available in Systema Naturae 2000	1f;3g;34s
1989-present	Systema Naturae 2000: 21 Nov 2025	[1f;3g;34s]
2016	J.P. Euzéby: [6 Sep 2017]	[1f;3g]
2007	G.M. Garrity et al.	[1f;3g;31s]
2001b	G.M. Garrity et al.: 3	[1f;3g]
2001	W. Zillig & A.-L. Reysenbach	[1f;2g]
2001a	G.M. Garrity & J.G. Holt: [156]	[1f;2g]
2000		1f2g