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A new species of Hippopotamidae based on abundant and well-preserved remains was discovered in the late Miocene levels of the Toros-Menalla fossiliferous area in the Djurab desert, Chad, central Africa. This hippopotamid is contemporaneous with Sahelanthropus tchadensis, a hominid from the same area, with an age of ca. 7.0 Ma. Hexaprotodon garyam sp. nov. is a large species with a robust, high mandibular symphysis. This feature is unknown in the Miocene East African hippos found at Lothagam, Kenya, but characterizes the Asian Hexaprotodon. This discovery enhances the heterogeneous character of the paraphyletic Hexaprotodon and indicates that the Hippopotamidae were a major component of the late Miocene environments in Central Africa as well as in East Africa.