Skull find in Ethiopia yields new clues on how humans evolved

The skull, known as "MRD", was discovered not far from the younger Lucy -- the ancient ancestor of modern humans

A "remarkably complete" 3.8-million-year-old skull of an early human has been unearthed in Ethiopia, scientists announced Wednesday, a discovery that has the potential to alter our understanding of human evolution.

The skull, known as "MRD", was discovered not far from the younger Lucy -- the ancient ancestor of modern humans -- and shows that the two species may have co-existed for about 100,000 years.