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 Genus Halomethanococcus Yu and Kawamura 1988, nom. dub. see Genus Methanohalophilus Paterek and Smith 1988