[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 Alphaproteobacteria Garrity et al. 2006
         Order Rhizobiales Kuykendall 2006
           Family Rhodobiaceae Garrity et al. 2006
             1 Genus Rhodobium Hiraishi et al. 1995
             2 Genus Parvibaculum Schleheck et al. 2004
             3 Genus Roseospirillum Glaeser and Overmann 2001