Researchers believe 17 skulls discovered in northern Spain's "Pit of Bones" cave belonged to early human ancestors that preceded the Neanderthals, according to a study published in the journal Science. The skulls, estimated to be about 430,000 years old, may shed new insights on how early humans evolved.
The skulls have thick brows and heavy jaws, but not the larger brain cavities seen in early Neanderthals, suggesting that evolution may have occured in distinct phases, with bigger brows and jaws arriving before bigger brains. These characteristics may have evolved separately, and very slowly, over hundreds of thousands of years, as the study's lead researcher, Juan Luis Arsuaga, explained to National Geographic.
Jean-Jacques Hublin, who studies at the Max Planck Institute for Evolutionary Anthropology in Leipzig, told NPR of the discovery that "if we understand how Neanderthals evolved and what has been going on, exactly, in the course of Neanderthal evolution, then we could say what is special with us, what is different."