Garrity GM, Bell JA, Lilburn TG. Taxonomic Outline of the Procaryotes. Bergey's Manual of Systematic Bacteriology, Second Edition, Release 4.0. Springer-Verlag, New York, 2003.
not validly published
The type order of this class has alternatively been placed in the class Methanothermea Cavalier-Smith 2002.Publication:
Cavalier-Smith T. The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification. Int J Syst Evol Microbiol 2002; 52:7-76.
The type order of this class has alternatively been placed in the class Methanococci Boone 2002.Publication:
Boone DR. Class II. Methanococci class. nov. In: Boone DR, Castenholz RW, Garrity GM (eds), Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 1 (The Archaea and the Deeply Branching and Phototrophic Bacteria), Springer, New York, 2001, p. 235-294.
Number of child taxa with a validly published and correct name: 3 Number of child taxa with a validly published name, including synonyms: 3 Total number of child taxa: 4