Domain Bacteria Woese et al. 1990
   Phylum Proteobacteria Garrity and Holt 2001 see Phylum Proteobacteria Garrity et al. 2005
     Class "Betaproteobacteria" Garrity et al. 2001 nom. ined. see Class Betaproteobacteria Garrity et al. 2006
       Order "Rhodocyclales" see Order Rhodocyclales Garrity et al. 2006
         Family "Rhodocyclaceae" see Family Rhodocyclaceae Garrity et al. 2006
           Genus Thauera Macy et al. 1993