La taxonomía aceptado actualmente se basa en la List of Prokaryotic names with Standing in Nomenclature (LPSN)[2] y Centro Nacional para la Información Biotecnológica[3]
y la filogenia es de 16S rRNA-based LTP lanzamiento 106 del All-Species Living Tree Project.[4]
Judicial Commission of the International Committee on Systematics of Prokaryotes (2005). «The nomenclatural types of the orders Acholeplasmatales, Halanaerobiales, Halobacteriales, Methanobacteriales, Methanococcales, Methanomicrobiales, Planctomycetales, Prochlorales, Sulfolobales, Thermococcales, Thermoproteales and Verrucomicrobiales are the genera Acholeplasma, Halanaerobium, Halobacterium, Methanobacterium, Methanococcus, Methanomicrobium, Planctomyces, Prochloron, Sulfolobus, Thermococcus, Thermoproteus and Verrucomicrobium, respectively. Opinion 79». Int. J. Syst. Evol. Microbiol.55 (Pt 1): 517-518. PMID15653928. doi:10.1099/ijs.0.63548-0.
Cavalier-Smith, T (2002). «The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification». Int. J. Syst. Evol. Microbiol.52 (Pt 1): 7-76. PMID11837318. doi:10.1099/00207713-52-1-7.
Euzeby JP; Tindall BJ (2001). «Nomenclatural type of orders: corrections necessary according to Rules 15 and 21a of the Bacteriological Code (1990 Revision), and designation of appropriate nomenclatural types of classes and subclasses. Request for an Opinion». Int. J. Syst. Evol. Microbiol.51 (Pt 2): 725-727. PMID11321122.
Boone, DR (2001). «Class I. Methanobacteria class. nov.». En DR Boone; RW Castenholz, eds. Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd edición). New York: Springer Verlag. pp. 169. ISBN978-0-387-98771-2.