Siberian Cave Yields Oldest Fossils Of Denisovans

Scientists have unearthed the oldest fossils to date of the mysterious human lineage known as the Denisovans.

Photo Insert: The first evidence of Neanderthal cousins, the Denisovans

With these 200,000-year-old bones, researchers have also for the first time discovered stone artifacts linked to these extinct relatives of modern humans, a new study finds, Charles Q. Choi reported for Live Science.

First identified a little more than a decade ago, the Denisovans, an extinct branch of the human family tree, are believed to be the closest known relatives of modern humans along with Neanderthals.

Analysis of DNA extracted from Denisovan fossils suggests they might have once been widespread across continental Asia, island Southeast Asia and Oceania, and revealed that at least two distinct groups of Denisovans interbred with ancestors of modern humans. The scientists detailed their findings online Nov. 25 in the journal Nature Ecology & Evolution.

Until now, scientists had only discovered half a dozen Denisovan fossils. Five were unearthed in Denisova Cave in Siberia, and one was found in a holy site in China, Live Science previously reported. Now, researchers have discovered another three Denisovan fossils in Denisova Cave.

Scientists estimated that they are about 200,000 years old, making them the oldest known Denisovans ever found. Previously, the earliest known Denisovan specimens were about 122,000 to 194,000 years old.

In the new study, researchers examined 3,791 bone scraps from Denisova Cave. They looked for proteins they knew were Denisovan based on previous DNA research on the extinct lineage.

Among these scraps, the scientists identified five human bones. Four of these contained enough DNA to reveal their identity — one was Neanderthal, and the other three were Denisovan.

Based on genetic similarities, two of these fossils may either come from one person or from related individuals.

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