Thaumatomastigidae

Typically biflagellated swimming or gliding cells capable of producing thin pseudopodia from one (ventral) face of the body which may be grooved. Mostly medium sized (15 - 50 µm). All species studied to date by electron microscopy have surface scales that form in association with the tubulocristate mitochondria; dictyosomes adpressed to anterior face of nucleus, and concentric extrusomes. Six genera are brought together here, but the distinctions between genera are not substantial and further work is desirable.