eukaryotes see Domain Eukaryota Chatton, 1925
   Kingdom Protozoa Goldfuss, 1818 [paraphyletic] - protozoa
     Subkingdom Sarcomastigota Cavalier-Smith, 1983 [paraphyletic] see [unranked] dorsates Cavalier-Smith, 2021
       Infrakingdom Opizoa Cavalier-Smith, 2021 [paraphyletic]
         Phylum Choanozoa Cavalier-Smith, 1981 [paraphyletic]
           Subphylum Choanofila Cavalier-Smith, 2009 [paraphyletic] see Superkingdom Holozoa Lang, O'Kelly, Nerad, Gray & Burger, 2002
             1 Class Ichthyosporea Cavalier-Smith, 1998
             2.1 Class Filasterea Cavalier-Smith, 2008
             2.2.1-n2 Class Choanoflagellatea Cavalier-Smith, 1998 [sister group to excluded taxa]