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 Percolozoa Cavalier-Smith, 1992
           Class Heterolobosea Page & Blanton, 1985
             Order Schizopyrenida Singh, 1952
               Genus Naegleria Aléxéieff, 1912