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 Spirochaetota Garrity and Holt 2021
                 Class Spirochaetiaᵀ Paster 2020
                   Order Spirochaetalesᵀ Buchanan 1917 (Approved Lists 1980)
                     Family Sphaerochaetaceae Hördt et al. 2020
                       1 Genus Pleomorphochaeta Arroua et al. 2017
                       2 Genus Sphaerochaetaᵀ Ritalahti et al. 2012
                       3 Genus "Candidatus Aphodenecus" Gilroy et al. 2022
                       4 Genus "Candidatus Ornithospirochaeta" Gilroy et al. 2022
                       5 Genus "Candidatus Physcosoma" Gilroy et al. 2022 nom. pro-inval.