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 Nanobdellati Rinke et al. 2024
                 Phylum Microcaldota Sakai et al. 2023 [monotypic]
                   Class Microcaldiaᵀ Sakai et al. 2023 [monotypic]
                     Order Microcaldalesᵀ Sakai et al. 2023 [monotypic]
                       Family Microcaldaceaeᵀ Sakai et al. 2023 [monotypic]
                         1 Genus Microcaldusᵀ Sakai et al. 2023