Palaeontologists working in Tanzania have discovered the oldest known fossils from two major primate groups — Old World monkeys, which include baboons and macaques, and apes, which include humans and chimpanzees. The study, published online today in Nature, reveals new information about primate evolution.

 

A team led by Nancy Stevens, a palaeontologist at Ohio University in Athens, recovered a lone tooth and a jaw fragment with three teeth from a site in the Rukwa Rift Basin in southwestern Tanzania. Precise geological dating of nearby rocks indicates that the fossils are 25.2 million years old, several million years older than any other example from either primate group.