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 [Serpula hyodysenteriae (Harris et al. 1972) Stanton et al. 1991] see Brachyspira hyodysenteriae (Harris et al. 1972) Ochiai et al. 1998