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 "Brachyspiraceae" nom. ined.] see Family Brachyspiraceae Paster 2012
                       [Genus Serpula Stanton et al. 1991 nom. illeg.] see Genus Serpulina Stanton 1992
                         1 [Serpula hyodysenteriae (Harris et al. 1972) Stanton et al. 1991] see Brachyspira hyodysenteriae (Harris et al. 1972) Ochiai et al. 1998
                         2 [Serpula innocens (Kinyon and Harris 1979) Stanton et al. 1991] see Brachyspira innocens (Kinyon and Harris 1979) Ochiai et al. 1998