Primate skeleton could give clues about human origins
5 June 2013 Last updated at 19:10 BST
A mouse-sized fossil from China has provided remarkable new insights into the origin of primates.
At 55 million years old, it represents the earliest known member of this broad group of animals that includes humans.
Scientists have called the diminutive creature Archicebus, which roughly translates as "ancient monkey".
They tell Nature magazine that its skeleton helps explain the branching that occurred at the very base of the primate evolutionary tree.
Our Science Correspondent, Pallab Ghosh reports.