living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Protozoa Goldfuss, 1818 see Kingdom Protozoa Goldfuss, 1818
         Phylum Sarcomastigophora Honigberg & Balamuth, 1963
           Subphylum Mastigophora Diesing, 1866 - flagellates
             Class Zoomastigophora see Class Zoomastigophorea
               Order Retortamonadida Grassé, 1952 - retortamonads
                 Family Retortamonadidae Wenrich, 1932
                   Genus Retortamonas Grassi, 1879
                     Retortamonas intestinalis (Wenyon & O'Connor, 1917) Wenrich, 1932