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 "Alphaproteobacteria" Garrity et al., 2006 [monotypic]
                 Class Alphaproteobacteriaᵀ Garrity et al. 2006
                   Order Rickettsiales Gieszczykiewicz 1939 (Approved Lists 1980)
                     Family Rickettsiaceae Pinkerton 1936 (Approved Lists 1980)
                       Genus Rickettsiaᵀ da Rocha-Lima 1916 (Approved Lists 1980)
                         Rickettsia rickettsii (Wolbach 1919) Brumpt 1922 (Approved Lists 1980)