prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
   Domain "Archaea" Woese et al. 1990
     Phylum "Euryarchaeota" Garrity and Holt 2001
       Class "Methanomicrobia"
         Order Methanosarcinales Boone et al. 2002
           Family Methanosarcinaceae Balch and Wolfe 1981
             1 Genus Halomethanococcus Yu and Kawamura 1988, nom. dub. see Genus Methanohalophilus Paterek and Smith 1988
             2 Genus Methanimicrococcus corrig. Sprenger et al. 2000
             3 Genus Methanococcoides Sowers and Ferry 1985
             4 Genus Methanohalobium Zhilina and Zavarzin 1988
             5 Genus Methanohalophilus Paterek and Smith 1988
             6 Genus Methanolobus König and Stetter 1983
             7 Genus Methanomethylovorans Lomans et al. 2004
             8 Genus Methanosalsum Boone and Baker 2002
             9 Genus Methanosarcina Kluyver and van Niel 1936 (Approved Lists 1980)