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 Salinispira Ben Hania et al. 2015 1.1 Genus Spirochaetaᵀ Ehrenberg 1835 (Approved Lists 1980) 1.2 Genus Sphaerochaeta Ritalahti et al. 2012 1.3 Genus Treponema Schaudinn 1905 (Approved Lists 1980) 2.1 Genus Clevelandina Bermudes et al. 1988 [monotypic] 2.2 Genus Diplocalyx (ex Gharagozlou 1968) Bermudes et al. 1988 [monotypic] 2.3 Genus Hollandina (ex To et al. 1978) Bermudes et al. 1988 [monotypic] 2.4 Genus Pillotina (ex Hollande and Gharagozlou 1967) Bermudes et al. 1988 [monotypic]