[living organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Prokaryota
     Kingdom Archaea Woese et al. 1990 see Domain Archaea Woese et al. 1990
       Phylum Euryarchaeota Garrity and Holt 2001
         Class Methanococci Boone 2002 [monotypic]
           Order Methanococcales Balch and Wolfe 1981