Phylum Parabasalia Honigberg, 1973 see Infraphylum Parabasalia Honigberg, 1973
   Class Trichomonadea Kirby, 1947
     Order Trichomonadida Kirby, 1947 - trichomonads
       Family Trichomonadidae Chalmers & Pekkola, 1918
         1 Genus Trichomonasᵀ Donné, 1836
         2.1 Genus Tetratrichomonas Parisi, 1910
         2.2 Genus Trichomonoides Brugerolle & Bordereau, 2004 see Genus Tetratrichomonas Parisi, 1910
         3 Genus Pentatrichomonas Mesnil, 1914
         4 Genus Pseudotrypanosoma Grassi, 1917
         5 Genus Trichomitopsis Kofoid & Swezy, 1919
         6 Genus Cochlosoma Kotlán, 1923
         7 Genus Pentatrichomonoides Kirby, 1931