Domain Bacteria Woese et al. 1990
   Phylum Proteobacteria Garrity and Holt 2001 see Phylum Proteobacteria Garrity et al. 2005
     Class "Gammaproteobacteria" nom. inval. see Class Gammaproteobacteria Garrity et al. 2005
       Order "Chromatiales" Garrity et al. 2001 nom. ined. see Order Chromatiales Imhoff 2005
         Family Chromatiaceae Bavendamm 1924 (Approved Lists 1980)
           Genus Allochromatium Imhoff et al. 1998
           Genus Amoebobacter Winogradsky 1888 (Approved Lists 1980) see Genus Thiocapsa Winogradsky 1888 (Approved Lists 1980)
           Genus Halochromatium Imhoff et al. 1998
           Genus Isochromatium Imhoff et al. 1998
           Genus Lamprobacter Gorlenko et al. 1988
           Genus Lamprocystis Schroeter 1886 (Approved Lists 1980)
           Genus Marichromatium Imhoff et al. 1998
           Genus Nitrosococcus Winogradsky 1892 (Approved Lists 1980)
           Genus Pfennigia Tindall 1999 see Genus Lamprocystis Schroeter 1886 (Approved Lists 1980)
           Genus Rhabdochromatium (ex Winogradsky 1888) Dilling et al. 1996
           Genus Thermochromatium Imhoff et al. 1998
           Genus Thiocapsa Winogradsky 1888 (Approved Lists 1980)
           Genus Thiococcus (ex Eimhjellen et al. 1967) Imhoff et al. 1998
           Genus Thiocystis Winogradsky 1888 (Approved Lists 1980)
           Genus Thiodictyon Winogradsky 1888 (Approved Lists 1980)
           Genus Thiohalocapsa Imhoff et al. 1998
           Genus Thiolamprovum Guyoneaud et al. 1998
           Genus Thiopedia Winogradsky 1888 (Approved Lists 1980)
           Genus Thiorhodococcus Guyoneaud et al. 1998
           Genus Thiorhodovibrio Overmann et al. 1993
           Genus Thiospirillum Winogradsky 1888 (Approved Lists 1980)
           1 Genus Chromatium Perty 1852 (Approved Lists 1980)