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 "Alphaproteobacteria" Garrity et al., 2006 [monotypic]
                 Class Alphaproteobacteriaᵀ Garrity et al. 2006
                   Order Caulobacterales Henrici and Johnson 1935 (Approved Lists 1980)
                     Family Caulobacteraceaeᵀ Henrici and Johnson 1935 (Approved Lists 1980)
                       1 Genus Caulobacterᵀ Henrici and Johnson 1935 (Approved Lists 1980)
                       2 Genus Asticcacaulis Poindexter 1964 (Approved Lists 1980)
                       3 Genus Brevundimonas Segers et al. 1994
                       4 Genus Phenylobacterium Lingens et al. 1985