Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Phylum "Spirochaetes" Garrity and Holt 2001 [monotypic]
               Class Spirochaetesᵀ Cavalier-Smith 2002 [monotypic]
                 Order Spirochaetalesᵀ Buchanan 1917 (Approved Lists 1980), sedis mutabilis
                   Family Spirochaetaceaeᵀ Swellengrebel 1907 (Approved Lists 1980)
                     Genus Spirochaetaᵀ Ehrenberg 1835 (Approved Lists 1980)
                       01 Spirochaeta africana Zhilina et al. 1996
                       02 Spirochaeta alkalica Zhilina et al. 1996
                       03 Spirochaeta americana Hoover et al. 2003
                       04 Spirochaeta asiatica Zhilina et al. 1996
                       05 Spirochaeta aurantia (ex Vinzent 1926) Canale-Parola 1980
                       06 Spirochaeta bajacaliforniensis Fracek and Stolz 2004
                       07 Spirochaeta caldaria Pohlschroeder et al. 1995
                       08 Spirochaeta cellobiosiphila Breznak and Warnecke 2008
                       09 Spirochaeta coccoides Dröge et al. 2006
                       10 Spirochaeta halophila Greenberg and Canale-Parola 1977 (Approved Lists 1980)
                       11 Spirochaeta isovalerica Harwood and Canale-Parola 1983
                       12 Spirochaeta litoralis (ex Hespell and Canale-Parola 1970) Canale-Parola 1980
                       13 Spirochaeta plicatilisᵀ Ehrenberg 1835 (Approved Lists 1980)
                       14 Spirochaeta smaragdinae Magot et al. 1998
                       15 Spirochaeta stenostrepta Zuelzer 1912 (Approved Lists 1980)
                       16 Spirochaeta thermophila Aksenova et al. 1992
                       17 Spirochaeta zuelzerae (ex Veldkamp 1960) Canale-Parola 1980