[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Spirochaetes" Garrity and Holt 2001
       Class "Spirochaetes" Cavalier-Smith, 2002 see Class Spirochaetes Cavalier-Smith 2002
         Order Spirochaetales Buchanan 1917 (Approved Lists 1980)
           Family Spirochaetaceae Swellengrebel 1907 (Approved Lists 1980)
             Genus Spirochaeta Ehrenberg 1835 (Approved Lists 1980)
               01 Spirochaeta stenostrepta Zuelzer 1912 (Approved Lists 1980)
               02 Spirochaeta africana Zhilina et al. 1996
               03 Spirochaeta alkalica Zhilina et al. 1996
               04 Spirochaeta americana Hoover et al. 2003
               05 Spirochaeta asiatica Zhilina et al. 1996
               06 [Spirochaeta aurantia] (ex Vinzent 1926) Canale-Parola 1980
               07 Spirochaeta bajacaliforniensis Fracek and Stolz 2004
               08 Spirochaeta caldaria Pohlschroeder et al. 1995
               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 plicatilis Ehrenberg 1835 (Approved Lists 1980)
               14 Spirochaeta smaragdinae Magot et al. 1998
               15 Spirochaeta thermophila Aksenova et al. 1992
               16 Spirochaeta zuelzerae (ex Veldkamp 1960) Canale-Parola 1980