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
               Clade discaria Cavalier-Smith, 2021
                 Clade natates Cavalier-Smith, 2021
                   Clade photaria Cavalier-Smith, 2021
                     Clade eucorta Cavalier-Smith, 2021
                       Superkingdom Corticata Lankester, 1878 - corticates
                         Kingdom Chromista Caval.-Sm. (1981) - chromists
                           Subkingdom Harosa Cavalier-Smith, 2010
                             [crown] Clade Sar Adl et al. 2012 [Simpson & Dunthorn 2020]
                               Infrakingdom Rhizaria Cavalier-Smith, 2002
                                 Phylum Retaria Cavalier-Smith, 2002
                                   Subphylum Radiozoa Cavalier-Smith, 1987
                                     Superclass Polycystinia Ehrenberg, 1838
                                       Class Sphaerellaria Haeckel, 1881
                                         Order Sphaerellataᵀ Haeckel, 1887
                                           Family Xiphostylidae Haeckel, 1881
                                             Subfamily Stylosphaerinae Haeckel, 1881
                                               Genus Stylatractus Haeckel, 1887
                                                 †Stylatractus universus Hays, 1970