prokaryotes - bacteria see Domain Bacteria Woese et al. 1990 Domain "Bacteria" Woese et al. 1990 Phylum "Spirochaetes" Garrity and Holt 2001 [monotypic] Class Spirochaetes Cavalier-Smith 2002 1 Order Brachyspirales Gupta et al. 2014 [monotypic] 2 Order Brevinematales Gupta et al. 2014 [monotypic] 3 Order Leptospirales Gupta et al. 2014 [monotypic] 4 Order Spirochaetales Buchanan 1917 (Approved Lists 1980)