Holding a Molar Tooth (IMAGE) U.S. National Science Foundation Caption This is a hand holding a molar tooth of a 20 million-year-old toxodont, a South American herbivore that lived in Argentina. Credit Regan Dunn 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.