Ancient Human Skull Reveals Our Ancestors Had an Inner Ear Like a Neanderthal

It turns out that our ancient ancestors may have more in common with Neanderthals than we first thought. After re-examining a 100,000-year-old archaic early human skull found 35 years ago in Northern China, researchers have found the presence of an inner-ear formation that was once thought to only occur in Neanderthals.

The findings came after recent micro-CT scans that revealed the interior configuration of a temporal bone in a fossilized human skull that was discovered in China's Nihewan Basin.

"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," said Erick Trinkaus, the co-author of the new study, in a news release. "It suggests, instead, that the later phases of human evolution were more of a labyrinth of biology and peoples than simple lines on maps would suggest."

The new scans completely surprised the researchers, which expected to see a temporal labyrinth that looked much like a modern human one. Instead, they saw a construction that was typical of a Neanderthal. In well-preserved mammal skull fossils, the semicircular canals are remnants of a fluid-filled sensing system that helps humans maintain their balance when they change spatial orientation. Yet a particular arrangement of the semicircular canals in the temporal labyrinth is typical of a Neanderthal.

"The study of human evolution has always been messy, and these findings just make it all the messier," said Trinkaus. "It shows that human populations in the real world don't act in nice simple patterns. Eastern Asia and Western Europe are a long way apart, and these migration patterns took thousands of years to play out. 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 findings are published in the journal Proceedings of the National Academy of Sciences.