[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
         1 Class Archaeoglobi Garrity and Holt 2002 [monotypic]
         2 Class Halobacteria Grant et al. 2002 [monotypic]
         3 Class Methanobacteria Boone 2002 [monotypic]
         4 Class Methanococci Boone 2002 [monotypic]
         5 Class "Methanomicrobia"
         6 Class Methanopyri Garrity and Holt 2002 [monotypic]
         7 Class "Nanohaloarchaea"
         8 Class Thermococci Zillig and Reysenbach 2002 [monotypic]
         9 Class Thermoplasmata Reysenbach 2002 [monotypic]