The Cave with Bones
In February 2002, a team of Romanian speleologists exploring a karst system in the southwestern Carpathian Mountains discovered a hidden chamber. The cave, named Peștera cu Oase ("The Cave with Bones"), was littered with the skeletal remains of Late Pleistocene cave bears (Ursus spelaeus). On the cave's surface, they found a complete lower jawbone, a human mandible. Designated "Oase 1," this fossil was directly dated by accelerator mass spectrometry to be between 37,000 and 42,000 years old. This age places it among the oldest known remains of early modern humans in Europe.
The physical form of the mandible presented a puzzle. It belonged to a modern human—it has a projecting chin, a feature absent in Neanderthals. Yet, it also possessed archaic characteristics. The jawbone has an exceptionally wide ramus (the vertical portion at the back) and its molars get progressively larger towards the back, with an unusually large third molar. These features are outside the typical range for modern humans and closer to those seen in Neanderthals and other archaic hominins. This mosaic of traits immediately suggested a complex ancestry and provided the first anatomical hints of interbreeding between modern humans and Neanderthals in Europe. Further discoveries in the cave, including a cranium from a second individual ("Oase 2"), confirmed this pattern of mixed modern and archaic features.