The oldest known fossils of an ape and a monkey have been uncovered, providing an intriguing glimpse of a crucial time in primate evolution.
The discoveries suggest that by 25 million years ago, two major groups of primates were distinct: one that today includes apes and humans and another that encompasses Old World monkeys such as baboons and macaques. Previous studies using living primates’ DNA suggested that ancient apes and Old World monkeys parted from a common ancestor between 25 million and 30 million years ago.
The new ape and monkey fossils, from Tanzania’s Rukwa Rift Basin, suggest that the evolutionary split between these primate lines must have occurred close to 30 million years ago, or perhaps even earlier, anthropologist Nancy Stevens of Ohio University in Athens and her colleagues conclude in the May 15 Nature.
Do you subscribe to the theory that apes and monkeys were once common ancestors?