[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010
       Class Betaproteobacteria Garrity et al. 2006
         Order Rhodocyclales Garrity et al. 2006
           Family Rhodocyclaceae Garrity et al. 2006
             Genus Azoarcus Reinhold-Hurek et al. 1993
               1 Azoarcus indigens Reinhold-Hurek et al. 1993
               2 Azoarcus anaerobius Springer et al. 1998
               3 Azoarcus buckelii Mechichi et al. 2002
               4 Azoarcus communis Reinhold-Hurek et al. 1993
               5 Azoarcus evansii Anders et al. 1995
               6 Azoarcus toluclasticus Song et al. 1999
               7 Azoarcus tolulyticus Zhou et al. 1995
               8 Azoarcus toluvorans Song et al. 1999