Discovery of Oldest Primate Skeleton Helps Chart Early Evolution of Humans, Apes

An international team of researchers has announced the discovery of the world’s oldest known fossil primate skeleton, an animal that lived about 55 million years ago and was even smaller than today’s smallest primate, the pygmy mouse lemur. The new specimen, named Archicebus achilles, was unearthed from an ancient lake bed in central China’s Hubei Province, near the course of the modern Yangtze River. In addition to being the oldest known example of an early primate skeleton, this almost complete new 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 discovery, described today in the journal Nature, also provides evidence that the earliest primates were active during the day, climbed trees, and primarily ate insects.