The significance of such archaeological recovery is amplified by the association with hunting of these animals by prehistoric man at possible Pre-Clovis horizons. Fossils of "Hippidion" have been found in:   "Hippidion" became extinct alongside the other South American equines at the end of the Late Pleistocene, between 15,000 and 10,000 years ago as part of the Quaternary extinction event, which resulted in the extinction of most large animals in both North and South America. Climactic modelling suggests that the preferred habitat for species of "Hippidion" declined after the Holocene transition, but the decline isn't enough to explain the extinction.