eukaryotes see Domain Eukaryota Chatton, 1925
   Kingdom Protozoa Goldfuss, 1818 [paraphyletic] - protozoa
     Subkingdom Sarcomastigota Cavalier-Smith, 1983 [paraphyletic] see [unranked] dorsates Cavalier-Smith, 2021
       Phylum Choanozoa Cavalier-Smith, 1981 [paraphyletic]
         Subphylum Choanofila Cavalier-Smith, 2009 [paraphyletic] see Superkingdom Holozoa Lang, O'Kelly, Nerad, Gray & Burger, 2002
           Class Choanoflagellatea Cavalier-Smith, 1998
             Order Craspedida Cavalier-Smith, 1997 [monotypic]
               Family Salpingoecidae Kent, 1880
                 1 Genus Choanoeca Ellis, 1930
                 2 Genus Codosiga James-Clark, 1866
                 3 Genus Monosiga Kent, 1880-1882
                 4 Genus Salpingoeca James-Clark, 1868