Schaeffer-Smith Monkey (IMAGE) Duke University Caption The critically endangered San Martin titi monkey (Callicebus oenanthe) lives in small family groups in Peru. Credit Proyecto Mono Tocón 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.