Prosynthetoceras is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America. It lived from the Early to Middle Miocene 20.6—13.6 Ma, existing for approximately 7 million years.[1] In appearance, Prosynthetoceras looked much like Syndyoceras, Kyptoceras, and Synthetoceras with three horns, one on the snout, and two above the eyes.