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 Spirochaetaceaeᵀ Swellengrebel 1907 (Approved Lists 1980)
                       Genus Spirochaetaᵀ Ehrenberg 1835 (Approved Lists 1980)
                         Spirochaeta aurantia (ex Vinzent 1926) Canale-Parola 1980
                           1 Spirochaeta aurantia subsp. aurantiaᵀ (Canale-Parola 1980) Canale-Parola 1984
                           2 Spirochaeta aurantia subsp. stricta Canale-Parola 1984