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 Chromatiales Imhoff 2005
                     Family Chromatiaceae Bavendamm 1924 (Approved Lists 1980)
                       Genus Marichromatium Imhoff et al. 1998
                         Marichromatium gracile (Strzeszewski 1913) Imhoff et al. 1998