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 Brachyspirales Gupta et al. 2014 [monotypic]
                     Family Brachyspiraceaeᵀ Paster 2012
                       [Genus Serpulina Stanton 1992] see Genus Brachyspira Hovind-Hougen et al. 1983
                         1 [Serpulina alvinipulli Stanton et al. 1998] see Brachyspira alvinipulli Stanton et al. 1998
                         2 [Serpulina hyodysenteriaeᵀ (Harris et al. 1972) Stanton 1992] see Brachyspira hyodysenteriae (Harris et al. 1972) Ochiai et al. 1998
                         3 [Serpulina innocens (Kinyon and Harris 1979) Stanton 1992] see Brachyspira innocens (Kinyon and Harris 1979) Ochiai et al. 1998
                         4 [Serpulina intermedia Stanton et al. 1997] see Brachyspira intermedia (Stanton et al. 1997) Hampson and La 2006
                         5 [Serpulina murdochii Stanton et al. 1997] see Brachyspira murdochii (Stanton et al. 1997) Hampson and La 2006
                         6 [Serpulina pilosicoli Trott et al. 1996] see Brachyspira pilosicoli (Trott et al. 1996) Ochiai et al. 1998