Skull Discovery Believed to Belong to Neanderthal, How Its Inner Ear Labyrinth Further Mystifies History of Human Evolution

The discovery of a Neanderthal skull in China is likely to bring forward new evidence of interbreeding and a more-complicated version of human evolution.

According to LiveScience.com, the new study, published in the journal Proceedings of the National Academy of Sciences, examines an inner ear surprisingly similar to that of modern man's closest extinct relatives. The study researchers will need more time to conduct further analyses, but they believe Neanderthals like the one whose remains were found in China interbred with other ancient human species.

Dubbed Xujiayao 15, the skull discovered 35 years ago in northern China is believed to have belonged to a Neanderthal and dates back 100,000 years ago. Neanderthals likely lived in Eurasia about 200,000 to 300,000 years ago and are the closest extinct relatives to modern humans. Past studies of ancient remains have suggested that several different human species lived alongside one another and likely interbred.

Study co-author Erik Trinkaus, an anthropologist at Washington University in St. Louis, told LiveScience.com the skull looked like a Neanderthal's but was certainly not a modern human's.

"We were very surprised," he said. "I said, 'My God, it looks like a Neanderthal.'"

The inner ear labyrinth of Xujiayao 15 suggests the Neanderthals in China interbred with another archaic human species that also lived at the time. But the team of researchers said they did not have sufficient evidence to make that conclusion.

"Eastern Asia and Western Europe are a long way apart, and these migration patterns took thousands of years to play out," Trinkaus said in a press release. "This study shows that you can't rely on one anatomical feature or one piece of DNA as the basis for sweeping assumptions about the migrations of hominid species from one place to another.

"The discovery places into question a whole suite of scenarios of later Pleistocene human population dispersals and interconnections based on tracing isolated anatomical or genetic features in fragmentary fossils."