Diplasiotherium is an extinct genus of herbivore litoptern belongs to the family Proterotheriidae, that lived between the late Miocene and the early Pliocene (in the SALMAs Huayquerian and Montehermosan). The fossils of this animal have been found in Argentina, in the Monte Hermoso Formation. Diplasiotherium is distinguished from other proterotheriids by the crown of its molars, which were higher than in other related genera (protohypsodont), and by its larger body size; the species D. robustum reached 395 kg in weight, making it the largest known proterotheriid.