A new analysis of an ape that lived 12.5 million years ago suggests it is a type of gorilla. If that’s true, it means gorillas evolved much earlier than thought, and also pushes back the time when humans split from chimps by about 2 million years.
David Begun of the University of Toronto in Canada reanalysed fossils of Dryopithecus apes, which lived in what is now Europe as early as about 12.5 million years ago. He says that the characteristics of the skull suggest that rather than evolving earlier than the great apes, as was previously thought, Dryopithecus was actually a great ape itself.
Features suggest Dryopithecus split from the human lineage about 14 million years ago, Begun says. From that, he says, we can extrapolate that the human lineage split from chimps about 10 million years ago.
That’s more than 2 million years earlier than the previous estimate based on the fossil record, but is actually close to recent estimates based on genetic analysis.
Current molecular clocks date the split between humans and chimps to at least 7 million years ago, matching the age of the oldest fossil thought to be in the human line, Sahelanthropus. But some reports quote molecular dates up to 13 million years.
Orang-utans are the earliest of the apes to have split from the human lineage, thought to be followed by Dryopithecus, then gorillas, then chimps. But if Dryopithecus is in fact a gorilla, that puts the species closer to humans and chimps.