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 Bacillatiᵀ (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Bacillotaᵀ Gibbons and Murray 2021
                 Class Clostridia Rainey 2010
                   Order Eubacteriales Buchanan 1917 (Approved Lists 1980)
                     Family Vallitaleaceae Quéméneur et al. 2019
                       Genus Petrocella Quéméneur et al. 2019