At 3.8 million years old, this mostly complete cranium of Australopithecus amanensis is the oldest australopith skull in the fossil record. (Credit: Dale Omori, courtesy of the Cleveland Museum of Natural History)

On Feb. 10, 2016, the face of a ghost emerged from weathered Ethiopian sandstone. The nearly complete skull, 3.8 million years old, was found less than 20 miles from the site where Lucy, the most famous of our distant evolutionary relatives, was discovered in the 1970s.

Lucy was