[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain "Archaea" Woese et al. 1990
     Phylum "Euryarchaeota" Garrity and Holt 2001
       Class "Methanomicrobia"
         Order Methanomicrobiales Balch and Wolfe 1981
           Family Methanomicrobiaceae Balch and Wolfe 1981
             1 Genus Methanomicrobium Balch and Wolfe 1981
             2 Genus Methanoculleus Maestrojuán et al. 1990
             3 Genus Methanofollis Zellner et al. 1999
             4 Genus Methanogenium Romesser et al. 1981
             5 Genus Methanolacinia Zellner et al. 1990
             6 Genus Methanoplanus Wildgruber et al. 1984