prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
   Domain "Bacteria" Woese et al. 1990
     Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010
       Class Gammaproteobacteria Garrity et al. 2005
         Order Chromatiales Imhoff 2005
           1 Family Chromatiaceae Bavendamm 1924 (Approved Lists 1980)
           2 Family Ectothiorhodospiraceae Imhoff 1984
           3 Family Granulosicoccaceae Lee et al. 2008 [monotypic]
           4 Family Halothiobacillaceae Kelly and Wood 2005
           5 Family Thioalkalispiraceae Mori et al. 2011
           6 Family Woeseiaceae Du et al. 2016 [monotypic]