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 Discicristata Cavalier-Smith, 1998
Phylum Euglenozoa Cavalier-Smith, 1981
Subphylum Saccostoma T. Cavalier-Smith, 1998
see Phylum Euglenozoa Cavalier-Smith, 1981
Class Postgaardea T. Cavalier-Smith, 1998
Order Postgaardida T. Cavalier-Smith, 2003
Genus Calkinsia Lackey, 1960