The understanding of human origins was turned on its head on Wednesday with the announcement of the discovery of fossils unearthed on a Moroccan hillside that are about 100,000 years older than any other known remains of our species, Homo sapiens.

Scientists determined that skulls, limb bones and teeth representing at least five individuals were about 300,000 years old, a blockbuster discovery in the field of anthropology.

The antiquity of the fossils was startling — a "big wow," as one of the researchers called it. But their discovery in North Africa, not East or even sub-Saharan Africa, also defied expectations. And the skulls, with faces and teeth matching people today but with archaic and elongated braincases, showed our brain needed more time to evolve its current form.