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
            
 1 Superclass Parabasalia Honigberg, 1973 - parabasalids
 see Infraphylum Parabasalia Honigberg, 1973
            
 2 Superclass Carpediemonadia T. Cavalier-Smith, 2003
            
 3 Superclass Eopharyngia (Cavalier-Smith, 1993) Cavalier-Smith, 2003