Archicebus Evolutionary Tree (IMAGE) American Museum of Natural History Caption A newly discovered primate fossil is crucial for illuminating a pivotal event in primate and human evolution--the divergence between the lineage leading to modern monkeys, apes, and humans (collectively known as anthropoids) and the branch leading to living tarsiers--small, nocturnal tree-dwelling primates. The relationships between these groups are shown in this diagram. Credit M.A. Klingler/Carnegie Museum of Natural History Usage Restrictions Can be used with appropriate credit 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.