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 "Parvularculales" [monotypic]
                     Family "Parvularculaceae"ᵀ Garrity et al., 2003
                       Genus Parvularculaᵀ Cho and Giovannoni 2003
                         1 Parvularcula bermudensisᵀ Cho and Giovannoni 2003
                         2 Parvularcula lutaonensis Arun et al. 2009
                         3 Parvularcula dongshanensis Yu et al. 2013