European researchers say they have identified a previously unknown species of proto-human that existed at least 1 million years until about 40,000 years ago.

The species left Africa about 1 million years ago and migrated as far as southern Siberia before it disappeared, the researchers said in a study published Wednesday in the scientific journal Nature. The conclusion was based on DNA analysis performed on a small bone fragment, excavated in a cave, that was the only physical remains of the species recovered by the researchers, The Washington Post reported.

Because the single fragment is all that has been recovered, researchers are unable to determine what the species looked like, how they lived and how they came to disappear.

Johannes Krause, a researcher at the Max Planck Institute for Evolutionary Anthropology in Germany and a leader of the research team, said the species lived in the Altai Mountains of Russia at around the same time as early modern humans and Neanderthals, the Post reported. It is not known whether the newly identified species -- which has yet to be named -- interacted or interbred with other types of people.

"Whoever carried this DNA out of Africa is some new creature that hasn't been on our radar screen so far," Krause said.

In a departure from previous techniques of analyzing and identifying anthropological discoveries, the newly reported species was identified solely through analysis of its genetic material, rather than through the use of skeleton size and shape, the report said.