An analysis based on fossilized animal tracks, oral tradition, archaeological findings, and the distribution and biology of dung beetles is presented to suggest that Copris subpunctatus Gillet (Coleoptera: Scarabaeidae) probably fed on bison dung and switched to cow dung after cattle were introduced by the Spanish colonizing effort. This transition probably took place before the bison apparently became extinguished in Costa Rica at the end of 19^th or beginning of the 20^th century.