life see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Prokarya see Domain Bacteria Woese et al. 1990
     Kingdom Bacteria (Cohn 1870) Cavalier-Smith 1983 - bacteria see Kingdom Bacteria Cavalier-Smith 2002
       Subkingdom Archaea Woese et al. 1990 see Domain Archaea Woese et al. 1990
         Division Mendosicutes Murray 1984 see Domain Archaea Woese et al. 1990
           Phylum Euryarchaeota Garrity and Holt 2001
             methanogens see Phylum Euryarchaeota Garrity and Holt 2001
               1 Genus Methanosarcina Kluyver and van Niel 1936 (Approved Lists 1980)
               2 Genus Methanobacterium Kluyver and van Niel 1936 (Approved Lists 1980)
               3 Genus Methanococcus Kluyver and van Niel 1936 (Approved Lists 1980)
               4 Genus Methanobacillus
               5 Genus Methanothrix Huser et al. 1983
               6 Genus Methanothermus Stetter 1982
               7 Genus Methanosaeta Patel and Sprott 1990 nom. illeg. see Genus Methanothrix Huser et al. 1983