Short Science, May 19, 2013

Newly unearthed ape and monkey fossils prove that the cousin species lived side-by-side in Africa as long as 25 million years ago, according to a study published in .

This is at least five million years earlier than fossil evidence has so far been able to show, according to a team of scientists from the United States, Australia and Tanzania.

"These discoveries suggest that the members of the major primate groups that today include apes and Old World monkeys were sharing the planet millions of years earlier than previously documented," said study co-author Nancy Stevens of Ohio University.

Old World monkeys (cercopithecoids) like baboons and macaques are found in Africa and Asia today, and are a distinct group from American or New World monkeys such as marmosets and spider monkeys.

Monkeys are part of the primate family that also includes apes, which fall in the hominoid sub-group with humans.

Scientists analysing modern primate DNA had already predicted that apes and monkeys must have split from a common ancestor about 25 to 30 million years ago, but the evidence has been lacking - the oldest fossils found to date were some 20 million years old. The new skull fragments, dug up in the Rukwa Rift Basin of Tanzania in 2011 and 2012, belonged to a previously unknown monkey named Nsungwepithecus gunnelli, and an ape dubbed Rukwapithecus fleaglei. AFP