Trailer: Netflix's "Cave of Bones," a documentary about the discovery that an extinct small-brained ape ritually buried their dead

Paleoanthropologist Lee Berger and his team have discovered a cave in Africa riddled with the bones of an extinct species, Homo naledi, a small hominin ape that lived 250,000 years ago, about when our own species, Homo sapien, was emerging.

Finding such a rich despository of bones of this species was a hugely significant find. But what Berger and his team found on full exploration of the cave system was startling. There was evidence that this small-brained creature (with a brain about the third the size of ours, and about the size of a chimpanzee's) used fire to explore the caves, ritually buried their dead there, and carved (primitive) art in the cave walls.

The implications for our understanding of our own evolution, and the evolution of brains, intelligence, culture, and religion are fascinating.

A new documentary, Cave of Bones, about Berger's team's findings will be released on July 17 on Netflix, and this trailer was posted on Wednesday.

In South Africa's Cradle of Humankind, Paleoanthropologist Lee Berger has found the world's oldest graveyard – and it's not human. If Lee and his team can prove that this ancient, small brained, ape-like creature practiced complex burial rituals – it will change everything we know about hominid evolution and the origins of belief.