Procaryotic Genera
   Domain "Bacteria" Woese et al. 1990
     Phylum Spirochaetes Garrity and Holt 2001 [monotypic]
       Class "Spirochaetes" Cavalier-Smith, 2002 [monotypic] see Class Spirochaetes Cavalier-Smith 2002
         Order Spirochaetales Buchanan 1917 (Approved Lists 1980)
           1 Family Spirochaetaceae Swellengrebel 1907 (Approved Lists 1980)
           2 Family "Serpulinaceae" see Family Brachyspiraceae nom. ined.
           3 Family Leptospiraceae Hovind-Hougen 1979 (Approved Lists 1980)