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?] Class "Nitrospira"ᵀ 2001 [monotypic] Order "Nitrospirales"ᵀ 2001 [monotypic] Family "Nitrospiraceae"ᵀ 2001 1 Genus Nitrospiraᵀ Watson et al. 1986 2 Genus Leptospirillum (ex Markosyan 1972) Hippe 2000 3 Candidatus "Magnetobacterium" Murray and Stackebrandt 1995 [monotypic] 4 Genus Thermodesulfovibrio Henry et al. 1994