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]
           Clade neomura Cavalier-Smith, 1987
             Domain Eukaryota Chatton, 1925 - eukaryotes
               ["Protista" Haeckel, 1866, incertae sedis] see Kingdom protists
                 [Grade "protozoa" Goldfuss, 1818 - protozoans]
                   [Phylum Sarcomastigophora Honigberg & Balamuth, 1963]
                     [Subphylum Mastigophora Diesing, 1866 - flagellates]
                       [Genus †Ruegenia Willems, 1992] see Genus Ruegenia H. Willems (1992)