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 "Enterobacteriales" Garrity and Holt 2001 nom. nud. [monotypic]
                     Family Enterobacteriaceaeᵀ Rahn 1937 (Approved Lists 1980)
                       Genus Proteus Hauser 1885 (Approved Lists 1980)
                         1 Proteus hauseri O'Hara et al. 2000
                         2 Proteus inconstans (Ornstein 1920) Shaw and Clarke 1955 (Approved Lists 1980)
                         3 Proteus mirabilis Hauser 1885 (Approved Lists 1980)
                         4 Proteus morganii (Winslow et al. 1919) Yale 1939 (Approved Lists 1980)
                         5 Proteus penneri Hickman et al. 1983
                         6 Proteus rettgeri (Hadley et al. 1918) Rustigian and Stuart 1943 (Approved Lists 1980)
                         7 Proteus vulgaris Hauser 1885 (Approved Lists 1980)