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 Eopharyngia (Cavalier-Smith, 1993) Cavalier-Smith, 2003
               Class Retortamonadea Grassé, 1952
                 1 Order Retortamonadida Grassé, 1952 - retortamonads