Researchers have uncovered ancient facial bones in a cave in northern Spain that may belong to an unknown prehistoric early human population, challenging established theories regarding when human ancestors first arrived in Western Europe.
The fossils discovered in Sima del Elefante, a cave in the Atapuerca Mountains of the Burgos province, are estimated to be between 1.1 million and 1.4 million years old. The remains, comprising approximately 80% of the left side of an adult’s face, include parts of the cheekbone, upper jaw, and nasal structure.
The discovery, detailed in a study published in Nature, suggests that Homo erectus, rather than Homo antecessor, may have been the first human ancestor to reach Western Europe. Until now, H. antecessor, a species found at multiple sites in the region since 1994, was believed to be the first hominin in the area.
The excavation team, led by paleoanthropologist Rosa Huguet of the Catalan Institute of Human Paleoecology and Social Evolution, discovered the fossil in 2022 while working at the cave site. A student was the first to spot the bones, triggering excitement among researchers.
“In this moment, we thought — 95% sure — that we had a human remain,” Huguet said.
After two years of analysis, researchers reconstructed the facial bones and determined they did not match H. antecessor, whose face was flat and vertical, similar to that of modern humans. Instead, the structure was more robust and projected outward, resembling the much older Homo erectus species.
“This paper introduces a new actor into the study of human evolution in Europe,” Huguet said.
Despite similarities to H. erectus, the fossil does not completely fit the species’ known characteristics. Because of this, scientists classified it as “H. aff. erectus,” meaning “similar to H. erectus” in Latin.
Sin palabras… demasiado emocionados para poder hablar.
Maria D. Guillén / IPHES-CERCA / Elena Santos / CENIEH@Nature @CENIEH @FATAPUERCA @iCERCA pic.twitter.com/Z0UMUK40Vd
— IPHES-CERCA (@iphes) March 12, 2025
The fossil, nicknamed “Pink” after Pink Floyd’s Dark Side of the Moon, belonged to an adult individual based on its worn molars. However, with only a partial skull, researchers could not determine the individual’s sex.
Future tooth enamel analysis may provide answers by identifying proteins that indicate male or female traits.
The discovery pushes back the timeline of human migration into Western Europe. Experts believe early hominins first left Africa about 1.8 million years ago, traveling through the Levantine corridor, a land route connecting Africa and Eurasia.
While H. erectus fossils are common in East Africa and Asia, remains of this age in Western Europe are extremely rare.
This is the third time we’ve found hominin fossils in unexpectedly deep layers in these caves, said María Martinón-Torres, a paleoanthropologist at the National Center for Research on Human Evolution.
