Skull found in Africa puts face on 'Lucy,' skeleton of early human ancestor

March 31, 1994|By New York Times News Service

The first reasonably complete skull of the earliest recognized human ancestors after the split-off from the great apes has been found near the bank of a dry riverbed in Ethiopia's arid badlands.

The skull, with its apelike heavy brow, jutting jaw and small brain case, is apparently that of a large male who lived 3 million years ago.

The remarkable find, which fills a serious gap in understanding early human evolution, gives a face to the species first identified and made famous by the discovery in 1974 of the headless "Lucy" skeleton.

Without a skull, scientists had not been sure what these creatures looked like or exactly what Lucy's position was in the human lineage.

The discovery could thus settle some of the hotly debated issues over whether the varied fossils from this time, between 3.9 million and 3 million years ago, actually belonged to a single species, known as Australopithecus afarensis and considered the common root of the human family tree, or represented two or more species of different sizes.

In a report to be published today in the journal Nature, the discoverers said the skull confirmed the "taxonomic unity of A. afarensis," that is, their original hypothesis that these creatures belonged to one species and not two, as other paleontologists had contended.

The discoverers described the skull as not only the youngest and largest, but also the only relatively intact one of the afarensis species, which lived for almost 1 million years in the region from Ethiopia in the north to Tanzania in the south.

The famous fossil footprints at Laetoli, in Tanzania, were presumably made by an afarensis adult and child out for a walk 3.5 million years ago. This is the earliest direct evidence for upright walking by human ancestors.

The longevity of the afarensis species was remarkable in itself, the discovery team said, noting how few detectable evolutionary changes seemed to occur between the first known afarensis specimens from 3.9 million years ago and the skull and other recently discovered fossils that are 3 million years old.

The team was headed by William Kimbel, director of paleoanthropology at the Institute of Human Origins in Berkeley, Calif.; Donald C. Johanson, president of the institute, and Yoel Rak, a paleontologist at Tel Aviv University in Israel.

Dr. Johanson was one of the discoverers of the Lucy fossils at a site about a mile away from where the skull was found, near the Awash River.

Finally to discover a skull was a personal triumph for him.

Although their report emphasized the skull's scientific implications, Dr. Johanson said in an interview that its emotional effect could not be discounted.

"Until you have a skull, until you can look into one of those big orbits [eye sockets] or hold a cranium in the cup of your hand," he said, "some people are not really satisfied that you have a new species."

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