http://www.guardian.co.uk/science/2010/jul/14/ape-ancestors-fossil-skull-saadanius

extract:

A fossilised, battle-scarred skull belonging to a previously unknown species of primate has been unearthed that sheds light on the evolutionary origins of apes, including humans.

The creature was no bigger than a baboon and lived in the canopy of a warm, damp forest near what is now the Red Sea in western Saudi Arabia, between 28m and 29m years ago.

The remains, which include a partial skull and teeth, were recovered from ironstone sediment during an expedition to the site in February 2009, but only now has a detailed description of the fossil been published.

The discovery, reported in Nature, is being hailed as one of the most significant finds in decades because it illuminates a critical moment in evolution when ancient primates split into two separate lineages.

One group of primates gave rise to the Old World monkeys, which include baboons and macaques, while the other led to the great apes and, ultimately, Homo sapiens.