Fossils Found in South Africa Point to Early Human Ancestors

Article excerpt

The fossil, nearly 2 million years old, 'may make a very good candidate' to be a new species of early human. Found in South Africa, it has a unique combination of ape-like and human features.

The eroded remains of a prehistoric limestone cave in South Africa have yielded fossils belonging to a new species of early human ancestor, an international research team announced Thursday.

Two sets of fossils, dated to around 1.95 million years ago, belonged to a female in her late 20s and a male 12 years old. They were found in a hilly area near Johannesburg known for its early human fossils.

The purported new species, Australopithecus sediba, "may make a very good candidate ancestor" to the genus Homo, which includes modern humans, says Lee Berger, a paleoanthropologist at the University of Witwatersrand in Johannesburg, who led a team that found the fossils. "Sediba might be a Rosetta Stone for defining for the first time just what the genus Homo is."

The researchers estimate that the individuals were roughly 4 to 4- 1/2 feet tall. They sported long, ape-like arms with small, powerful hands, indicating that they still frequently used trees for protection. But hip bones associated with both individuals are human- like, indicating that they were competent upright walkers.

Unique combination of features

The partial skeletons the team found "have a combination of features that we have not seen before," says Rick Potts, a paleoanthropologist and director of the human-origins program at the Smithsonian Institution's National Museum of Natural History in Washington.

Yet he adds that it's a bit early to label the find a new species. The discovery represents a single snapshot in time, so it's unclear if the individuals the team found represent the tip of a dead-end branch of Australopithecus, or something truly along the direct line from Australopithecus to Homo.

Still, the find is remarkable on several levels, researchers say, all the more so because this is a poorly represented time period in the fossil record for early humans. The bones are exceptionally well preserved compared with many other early-human fossils found in Africa.

Moreover, many finds come as disparate bones. The fossils from the two new individuals include skeletal segments that remain connected - portions of a hand to a forearm for instance, or a complete upper arm and forearm. That makes it easier to spot features that help researchers place the species in the broader context of human evolution.

Site contains well-preserved animals too

And the site contains equally well-preserved remains of saber- tooth cats, mice, wild dogs and cats, hyenas, and horses, putting the new hominins in a broader environmental context. …