A new species of amphistome digenean from the stomach and intestine of Podocnemis expansa (Pelomedusidae), of the tropical rain forest, from the State of Pará, Brazil, is described and allocated to a new genus (Oriximinatrema noronhae). The new species is characterized by the presence of an esophageal bulb, an esophageal extension uncovered by an extension of the pharyngeal sacs, a well-developed cirrus sac, post-bifurcal genital sucker, a ventro-terminal acetabulum with an anterior lip, and medium-sized eggs. This is the first report of a Dadayiinae trematode infecting a reptilian host.