Thursday, April 08, 2010

New Hominid species found in South Africa

Excerpts of New Hominid Species Discovered in South Africa By CELIA W. DUGGER and JOHN NOBLE WILFORD, New York Times

Scientists announced Thursday that he had found the bones of a new hominid species that lived almost two million years ago during the fateful, still mysterious period spanning the emergence of the human family.

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 the seSotho language, strode upright across the landscape 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, Dr. Berger said.

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

Dr. Berger's team said in the journal that the new species probably descended from Australopithecus africanus. At a news 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.

Researchers now think the split between apes and the hominid lineage occurred around seven million years ago in Africa. The sparse fossil record shows early hominid species already walking upright, but still relatively apelike. Small australopithecines, with bodies and brains not much bigger than those of modern chimpanzees, were widespread from 3.8 million to 3 million years ago, most famously Australopithecus afarensis like Lucy.

Just when changes leading to Homo were happening remains unclear in the fossil record. Hominids started shaping stone tools about 2.6 million years ago. Hominids identified as Homo appeared more than 2 million years ago, their direct ancestry anything but clear. The species Au. sediba thus shared a time with Homo habilis and Homo erectus.

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