Hollywood couldn't have scripted a more perfect scene: A nine-year-old boy, tagging along on his father's archeological expedition to Cradle of Humankind, South Africa, is chasing his dog through the grass one morning when he literally stumbles across some fossilized bones. But these aren't any ho-hum, add-them-to-the-pile bones: They represent an entirely new hominid species, almost two million years old, which walked upright like modern humans but still had apelike arms for climbing trees.
The discovery adds a new twist to the story NOVA told in last fall's Becoming Human. As Rick Potts, director of the Smithsonian's Human Origins Program, told the New York Times, "It reminds us of the combining and recombining of characteristics, the tinkering and experimentation, that go on in evolution."
Where does this new species, dubbed Australopithecus sediba (meaning "fountain" or "wellspring"), sprout on the tree of human origins? Lee Berger, who lead the science team, says that it probably descended from Australopithecus africanus. From there, it's not yet clear whether the species was a direct human ancestor or a "side branch" that budded and then petered out.