Kingdom Protozoa Goldfuss, 1818 - protozoa
   Subkingdom Corticata Lankester, 1878 see Subkingdom Biciliata
     Infrakingdom Excavata T. Cavalier-Smith, 2002 see Supergroup Excavata Cavalier-Smith, 2002
       Superphylum Eozoa Cavalier-Smith, 1997 see Infrakingdom Eozoa Cavalier-Smith, 1997
         Phylum Metamonada Grassé, 1952
           Subphylum Trichozoa Cavalier-Smith, 1997
             Superclass Parabasalia Honigberg, 1973 - parabasalids see Infraphylum Parabasalia Honigberg, 1973
               Class Trichomonadea Kirby, 1947
                 1 Order Trichomonadida Kirby, 1947 - trichomonads
                 2 Order Lophomonadida Light, 1927
                 3 Order Spirotrichonymphida Grassé, 1952