Ancient skulls found in China could belong to an unknown human species

Scientists have discovered two partial human skulls in central China that they say could potentially belong to an unknown archaic human species.

The skulls are 105,000 to 125,000 years old, and they contain a unique mix of modern human and Neanderthal features. Excitingly, they could be the key to filling in some of the missing pieces of the human family tree in east Asia.

Xiujie Wu

Without DNA analysis, the team is reluctant to speculate about the owners of the skulls, but they've suggested that the remains could potentially represent a new, archaic human species that we haven't previously stumbled upon.

That's not as unlikely as it sounds - there are hints in our genetic records that there are still significant missing ancestors on our family tree we're yet to uncover.

But there's also another possibility.

Something the researchers didn't speculate on in their paper is that the skulls could be rare physical evidence of the Denisovans, a mysterious cousin of Neanderthals that are thought to have lived between 100,000 and 50,000 years ago.

It's estimated that modern humans living in China contain around 0.1 percent Denisovan DNA, which suggests that at some point modern humans lived alongside and bred with the Denisovans.

But other than a lone finger bone and a couple of teeth found in a Siberian cave in 2008, we have very little trace of them in the fossil record, so it's been hard to piece the story together.

The research has been published in Science