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?]
             Superphylum "Proteobacteria" Craig et al. 2010
               Phylum "Gammaproteobacteria" Garrity et al., 2005 [monotypic]
                 Class Gammaproteobacteriaᵀ Garrity et al. 2005
                   Order Legionellales Garrity et al. 2005
                     Family Coxiellaceae Garrity et al. 2005
                       1 Genus Coxiellaᵀ (Philip 1943) Philip 1948 (Approved Lists 1980) [monotypic]
                       2 Genus Aquicella Santos et al. 2004
                       3 Genus Diplorickettsia Mediannikov et al. 2011 [monotypic]