First Incisor (IMAGE) Proceedings of the National Academy of Sciences Caption This is an anthropogenically modified deciduous, upper left first incisor from the site of Uguumur, Zavkhan, central Mongolia, recovered from a ritual horse burial belonging to the late Bronze Age. Credit PNAS Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.