[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 Caulobacterales Henrici and Johnson 1935 (Approved Lists 1980)
           Family Caulobacteraceae Henrici and Johnson 1935 (Approved Lists 1980)
             Genus Caulobacter Henrici and Johnson 1935 (Approved Lists 1980)
               Caulobacter leidyi corrig. Poindexter 1964 (Approved Lists 1980)