Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum "Proteobacteria" Craig et al. 2010
               Phylum "Betaproteobacteria" Garrity et al., 2006 [monotypic]
                 Class Betaproteobacteriaᵀ Garrity et al. 2006
                   Order Rhodocyclales Garrity et al. 2006 [monotypic]
                     Family Rhodocyclaceaeᵀ Garrity et al. 2006
                       Genus Azoarcus Reinhold-Hurek et al. 1993
                         1 Azoarcus anaerobius Springer et al. 1998
                         2 Azoarcus buckelii Mechichi et al. 2002
                         3 Azoarcus communis Reinhold-Hurek et al. 1993
                         4 Azoarcus evansii Anders et al. 1995
                         5 Azoarcus indigens Reinhold-Hurek et al. 1993
                         6 Azoarcus toluclasticus Song et al. 1999
                         7 Azoarcus tolulyticus Zhou et al. 1995
                         8 Azoarcus toluvorans Song et al. 1999