World and Nation

Unearthing human ancestor is child’s play in South Africa

Nine-year-old Matthew Berger dashed after his dog, Tau, into the high grass here one sunny August morning in 2008, tripped over a log and stumbled onto a major archeological discovery. Scientists announced Thursday that he had found the bones of a new hominid species that lived almost 2 million years ago during the fateful, still mysterious period spanning the emergence of the human family.

“Dad, I found a fossil!” Matthew said he cried out to his father, Lee R. Berger, an American paleoanthropologist, who had been searching for hominid bones just a hill-and-a-half away for almost two decades. Fossil hunters have profitably scoured these rolling grasslands north of Johannesburg since the 1930s.

Matthew held the ancient remains of a 4-foot-2 boy who had been just a few years older than Matthew himself. Berger, with the Institute for Human Evolution at the University of the Witwatersrand in Johannesburg, and his fellow researchers have since found much more of the boy’s skeleton, including his extraordinarily well-preserved skull, and three other individuals. South Africa’s children will compete to name the boy.

In a report being published Friday in the journal Science, Berger, 44, and a team of scientists said the fossils from the boy and a woman were a surprising and distinctive mixture of primitive and advanced anatomy and thus qualified as a new species of hominid, the ancestors and other close relatives of humans. It has been named Australopithecus sediba.

The species sediba, which means fountain or wellspring in Sotho, strode upright on long legs, with human-shaped hips and pelvis, but still climbed through trees on apelike arms.

It had the small teeth and more modern face of Homo, the genus that includes modern humans, but the relatively primitive feet and “tiny brain” of Australopithecus, Berger said.

Geologists estimated that the individuals lived 1.78 million to 1.95 million years ago, probably closer to the older date, when australopithecines and early species of Homo were contemporaries.

Berger’s team said that the new species probably descended from Australopithecus africanus. At a teleconference on Wednesday, he described the species as a possible ancestor of Homo erectus, an immediate predecessor to Homo sapiens, or a close “side branch” that did not lead to modern humans.