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]
           Domain Bacteria Woese et al. 2024
             Kingdom Pseudomonadati (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Chlamydiota Garrity and Holt 2021 [monotypic]
                 Class Chlamydiiaᵀ Horn 2016 [monotypic]
                   Order Chlamydialesᵀ Storz and Page 1971 (Approved Lists 1980)
                     Family Simkaniaceae Everett et al. 1999
                       1 Genus Simkaniaᵀ Everett et al. 1999 [monotypic]
                       2 Genus "Candidatus Fritschea" Everett et al. 2005
                       3 Genus "Candidatus Neptunichlamydia" corrig. Pizzetti et al. 2020
                       4 Genus "Candidatus Syngnamydia" Fehr et al. 2020
                       5 Genus "Candidatus Amphrikana" Davison and Hurst 2023 nom. pro-inval.