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 Pseudomonadotaᵀ Garrity et al. 2021
                 Class Oligoflexia Nakai et al. 2014
                   Order Silvanigrellales Hahn et al. 2017 [monotypic]
                     Family Silvanigrellaceaeᵀ Hahn et al. 2017
                       Genus Fluviispira Pitt et al. 2020