A human skull more than 200,000 years old has been found in Greece, upending scientists' current understanding of when we left Africa.
The skull was found in a cave in the 1970s and written off as belonging to a Neanderthal, but new analysis has shown it's Homo sapiens - just like us, except 210,000 years old.
Until now, it's believed modern humans didn't reach Europe until about 45,000 years ago - so this new find could rewrite the prehistory books.
"It shows that the early dispersal of Homo sapiens out of Africa not only occurred earlier, before 200,000 years ago, but also reached further geographically, all the way to Europe," palaeoanthropologist Katerina Harvati of the University of Tuebingen, Germany, told AFP.
It's by far the oldest skull belonging to a modern human found outside of Africa. Homo sapiens only emerged as a distinct species about 350,000 years ago.
According to present theories, Homo sapiens interbred with and gradually replaced Neanderthals. But the skull, dubbed Apidima 1 after the cave it was found in, was 40,000 years old than a second skull found in the same place - which belonged to a Neanderthal.
"Our results suggest that at least two groups of people lived in the Middle Pleistocene in what is now southern Greece: an early population of Homo sapiens and, later, a group of Neanderthals," said Dr Harvati.
"We hypothesise that, as in the Near East, the early modern human population represented by Apidima 1 was probably replaced by Neanderthals, whose presence in southern Greece is well-documented, including by the Apidima 2 skull from the same site."
The Neanderthals, in turn, were replaced by bigger waves of later Homo sapiens.
Despite being separated by 40,000 years, the skulls were found just 30cm apart after being washed through the cave system about 150,000 years ago, the evidence suggests.
"This evidence from Apidima, along with other discoveries, demonstrates that, on more than one occasion, modern humans kept pushing north and westwards from Africa and the Levant into Europe," Eric Delson of the New York Consortium in Evolutionary Primatology wrote in Nature.
"Rather than a single exit of hominins from Africa to populate Eurasia, there must have been several dispersals, some of which did not result in permanent occupations by these hominins and their descendants."
The previous oldest Homo sapiens remains found outside of Africa, at up to 194,000 years old, were discovered in Israel just last year.
"All of these early Eurasian human fossils seem to represent what might be called ‘failed’ dispersals from Africa - they reached the Middle East and southeastern Europe, but did not persist in these regions," Delson wrote.
"There is evidence that these populations were replaced at these or neighbouring sites by Neanderthals."
The new study was published Thursday in Nature.