procaryotes
   Domain Archaea Woese et al. 1990 stat. inval. see Domain Archaea Woese et al. 2024
     Phylum Euryarchaeota Garrity and Holt 2002 stat. inval. see Kingdom Methanobacteriati (Garrity and Holt 2023) Oren and Göker 2024
       Class Methanococci Boone 2001 nom. inval. see Class Methanococci Boone 2002
         Order Methanosarcinales Boone et al. 2001 nom. inval. see Order Methanosarcinales Boone et al. 2002
           Family Methanosarcinaceae Balch and Wolfe 1981
             Genus Methanococcoides Sowers and Ferry 1985