A class of flagellates (superclass Mastigophora) within the phylum Sarcomastigophora (flagellate and ameboid protozoans), of animalian as opposed to plantlike characteristics. Chromatophores are absent; one to many flagella are found, although they may be absent in ameboid forms; sexuality is known in some groups. It includes many human parasites such as the trypanosomes and trichomonads, as well as a number of other parasitic and symbiotic forms. SYN: Zoomastigina, Zoomastigophorasida. [zoo- + G. mastix, whip, + phoros, bearing]
