The Plagiorchiida are a large order of flatworms. They belong to the Digenea, a large subclass of flukes. Unlike the related Echinostomida and Strigeidida, they contain relatively few significant parasites of humans.The following suborders are placed here: Allocreadiata Skrjabin, Petrow, Koval, 1958 Eucotylata Odening, 1961 Opecoelata Odening, 1960 Plagiorchiata Troglotremata Schell, 1980 Zoogonata Odening, 1961