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 Alphaproteobacteria Garrity et al. 2006
         Order Rhizobiales Kuykendall 2006
           Family Xanthobacteraceae Lee et al. 2005
             1 Genus Ancylobacter Raj 1983
             2 Genus Azorhizobium Dreyfus et al. 1988
             3 Genus Labrys Vasilyeva and Semenov 1985
             4 Genus Pseudolabrys Kämpfer et al. 2006
             5 Genus Pseudoxanthobacter Arun et al. 2008
             6 Genus Starkeya Kelly et al. 2000
             7 Genus Xanthobacter Wiegel et al. 1978 (Approved Lists 1980)