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?]
             Phylum "Epsilonproteobacteria" Garrity et al., 2006
               Class Epsilonproteobacteriaᵀ Garrity et al. 2006
                 Order Campylobacterales Garrity et al. 2006
                   1 Family Campylobacteraceaeᵀ Vandamme and De Ley 1991
                   2 Family Helicobacteraceae Garrity et al. 2006
                   3 Family "Hydrogenimonaceae" Garrity et al. 2004 nom. nud. [monotypic]