Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Clade neomura Cavalier-Smith, 1987
             Domain Archaea Woese et al. 2024 [paraphyletic]
               Kingdom Promethearchaeati Imachi et al. 2024 [monotypic]
                 Phylum Promethearchaeotaᵀ Imachi et al. 2024 [paraphyletic]
                   Class "Candidatus Freyarchaeia" Valentin-Alvarado et al. 2024 nom. pro-inval. [monotypic]
                     Family "Candidatus Freyarchaeaceae"ᵀ Valentin-Alvarado et al. 2024 nom. pro-inval. [monotypic]
                       1 Genus "Candidatus Freyarchaeum"ᵀ Valentin-Alvarado et al. 2024 nom. pro-inval.