Monkey and Ape Mandibles (IMAGE) University of California - Berkeley Caption A baboon mandible (lower jawbone) on the left and gorilla on the right, representing the two major primate groups studied: monkey and ape, respectively. Credit Leslea Hlusko, UC Berkeley 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.