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 Bacteroidota Krieg et al. 2021
                 Class Bacteroidiaᵀ Krieg 2012 [monotypic]
                   Order Bacteroidalesᵀ Krieg 2012
                     Family Rikenellaceae Krieg et al. 2012
                       1 Genus Alistipes Rautio et al. 2003
                       2 Genus Anaerocella Abe et al. 2013 [monotypic]
                       3 Genus Gallalistipes Zenner et al. 2021
                       4 Genus Mucinivorans Nelson et al. 2015 [monotypic]
                       5 Genus Rikenellaᵀ Collins et al. 1985 [monotypic]
                       6 Genus "Candidatus Avirikenella" Gilroy et al. 2022