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 Planctomycetota Garrity and Holt 2021
                 Class Planctomycetiaᵀ Ward 2020
                   Order Isosphaerales Dedysh et al. 2020 [monotypic]
                     Family Isosphaeraceaeᵀ Kulichevskaya et al. 2016
                       1 Genus Aquisphaera Bondoso et al. 2011 [monotypic]
                       2 Genus Isosphaeraᵀ Giovannoni et al. 1995 [monotypic]
                       3 Genus Kueselia Kündgen et al. 2026
                       4 Genus Paludisphaera Kulichevskaya et al. 2016
                       5 Genus Singulisphaera Kulichevskaya et al. 2008 [monotypic]
                       6 Genus Tautonia Kovaleva et al. 2019
                       7 Genus Tundrisphaera Kulichevskaya et al. 2017