Fossils found deep in South Africa's Rising Star cave complex in 2013 have been dated by several expert teams with their findings suggesting the hominids, called Homo naledi, may have lived alongside Homo sapiens.
It had previously been thought that the hominids were millions of years old.
A team of 20 scientists from laboratories and institutions around the world, including in South Africa and Australia, established the age of the fossils which suggests that Homo naledi may well have lived at the same time as humans. Their findings have been published Tuesday in three papers in the journal eLife.
The focus of the team's research has been South Africa's barely accessible Rising Star Cave system, part of the Cradle of Humankind World Heritage Site, about 50 kilometres (30 miles) northwest of Johannesburg. The area has been an incredibly rich source of artefacts for palaeontologists since it was first discovered.
"There has been a great deal of speculation on how old Homo naledi was... Everyone who has examined the anatomy of Homo naledi has suggested that it would be in the millions of years," said project leader and researcher at Wits University, Lee Berger.
But now, having established the age of the fossils using six independent methods, the team estimates that they are between 236,000 and 335,000-years-old -- the beginning of the rise of modern human behaviour, said Berger.
Researcher John Hawks said that the separate discovery of new Homo naledi fossils -- including a pristine skull -- in two other caves "confirmed that we're looking at an anatomical pattern that is very different from any other common species".
Some experts disputed the findings of the team that discovered the initial fossils and named the new species Homo naledi, arguing that they were merely early Homo erectus.
