Story highlights

Scientists say they have discovered a new species of human relative in South Africa

"Homo naledi" appears to have buried its dead -- a behavior previously though limited to humans

The discovery could transform our understanding of human evolution

Rising Star Cave, South Africa CNN  — 

When an amateur caver and university geologist arrived at Lee Berger’s house one night in late 2013 with a fragment of a fossil jawbone in hand, they broke out the beers and called National Geographic.

Berger, a professor at the University of the Witwatersrand in Johannesburg, South Africa, had unearthed some major finds before. But he knew he had something big on his hands.

What he didn’t know at the time is that it would shake up our understanding of the progress of human evolution and even pose new questions about our identity.

Two years after they were tipped off by cavers plumbing the depths of the limestone tunnels in the Rising Star Cave outside Johannesburg, Berger and his team have discovered what they say is a new addition to our family tree.

The team is calling this new species of human relative “Homo naledi,” and they say it appears to have buried its dead – a behavior scientists previously thought was limited to humans.

Berger’s team came up with the startling theory just days after reaching the place where the fossils – consisting of infants, children, adults and elderly individuals – were found, in a previously isolated chamber within the cave.

The team believes that the chamber, located 30 meters underground in the Cradle of Humanity world heritage site, was a burial ground – and that Homo naledi could have used fire to light the way.