The Pleistocene localities of Aguada de Lomas and Sacaco have yielded numerous equid fossils that were at first referred to Equus (Amerhippus) santaeelenae (Salas et al., 2004).
After further comparisons, in particular with fossils from Tarija (Bolivia) it appears that they more probably belong to Equus (Amerhippus) insulatus. So does the cranium from El Jahvay (Fig. 1, 2).