[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
           1 Family Methanomicrobiaceae Balch and Wolfe 1981
           2 Family Methanocorpusculaceae Zellner et al. 1989
           3 Family Methanospirillaceae Boone et al. 2002
           4 Genus Methanocalculus Ollivier et al. 1998