prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
Status: extant
   Domain "Archaea" Woese et al. 1990
  Status: extant
     Phylum "Euryarchaeota" Garrity and Holt 2001
    Status: extant
       Class Methanococci Boone 2002 [monotypic]
      Status: extant
         Order Methanococcales Balch and Wolfe 1981
        Status: extant
           Family Methanococcaceae Balch and Wolfe 1981
          Status: extant
             Genus Methanococcus Kluyver and van Niel 1936 (Approved Lists 1980)
            Status: extant