Deep inside a Portuguese cave, the fossil of a human cranium lay buried for 400,000 years, surrounded by a smattering of stone tools and animal remains.
A team of archeologists recently retrieved the fossil, unearthing a new understanding of how humans evolved in western Europe during the middle Pleistocene — a period that spanned roughly 781,000 to 126,000 years ago.
The cranium found in Portugal’s Aroeira cave belonged to a Neanderthal, the closest extinct relative of modern humans.
Researchers say it’s the oldest human fossil ever found in Portugal and shares some features with other fossils found in Spain, France and Italy from the same period. The cranium is also one of the earliest human fossils in Europe to be connected to prehistoric stone tools, according to a study published Monday in the Proceedings of the National Academy of Sciences.
“The Aroeria cranium increases the anatomical diversity in the human fossil record from this time period, suggesting different populations showed somewhat different combinations of features,” Rolf Quam, a co-author of Monday’s study and an anthropologist from Binghamton University in New York, said in a news release.
“This is an interesting new fossil discovery from the Iberian Peninsula, a crucial region for understanding the origin and evolution of the Neanderthals,” Quam said.
A 400,000-year-old fossil is rare but still relatively young in the world of paleontology.
Two fossil jaws found recently in Ethiopia suggest the human genus, Homo, arrived in East Africa around 2.8 million years ago. The remains of Lucy, a famous early human ancestor, indicate she roamed present-day Ethiopia some 3.2 million years ago.
Quam led the Aroeira cave study with Portuguese archaeologist João Zilhão. Their international team found the cranium on the last day of the 2014 archeological field season. Since the fossil was firmly cemented in the sediment, researchers removed it from the site in a solid block.
At a paleontology research center in Madrid, experts extracted and restored the cranium over a “painstaking” two-year process, Quam said. Next, researchers CT-scanned the fossil and made virtual reconstructions.
The fossil will be the centerpiece of a human evolution exhibit at the National Archeology Museum in Lisbon, Portugal, this October.