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 Thermoproteati Guy and Ettema 2024
                 Phylum Thermoproteotaᵀ Garrity and Holt 2021
                   Order "Candidatus Nitrosocaldales" De La Torre et al. 2020 [monotypic]
                     Family "Candidatus Nitrosocaldaceae"ᵀ De La Torre et al. 2020
                       Genus "Candidatus Nitrosocaldus"ᵀ De la Torre et al. 2020