Manchester Online, United Kigdom
Thursday, 13th April 2006
A CACHE of fossils found in an Ethiopian desert are to provide the missing link between 3.5 million-year-old ape-men and earlier human ancestors.
The bones belong to the most primitive species of Australopithecus, known as Au. anamensis, and date from about 4.1 million years ago.
Australopithecenes have been dubbed "ape-men" because they were hairy, short, small-brained, and big-toothed but walked on two legs.
The newly discovered fossils fill the gap between Australopithecenes and the much more ape-like Ardipithecenes, which lived between 4.4 million and 7 million years ago.
Since the first Australopithecus skull, the Taung child, was found in South Africa 82 years ago, more of the hominid's fossils spanning a three million-year time period have turned up all over Africa.
The most famous was "Lucy", a 3.5 foot adult skeleton, discovered in the Afar desert of eastern Ethiopia in 1974.
The creature, named Au. afarensis, lived between 3.6 million and 3 million years ago and was unearthed in the same region that yielded the latest finds.
Australopithecus had much larger teeth than Ardipithecus, allowing it to live on a broad diet of tough, fibrous plants.
The teeth of the more primitive Ardipithecus were adapted to a diet of softer, less abrasive food.
Professor Tim White, from the University of California at Berkeley, USA, one of the leaders of the team that discovered the fossils, said: "Australopithecus became a superior omnivore, able to eat tubers and roots with more fibre and grit, adapting it better to times of scarcity during periods of extended drought.
"They may have been small brained, but they stuck around a long time, fully half of our zoological family's 6 million-year existence on the planet."
The scientists believe Australopithecus evolved from some species of Ardipithecus.
In all, teeth and jawbones of eight individuals were found, all dated to about 4.1 million years ago.
A partial thigh bone and hand and foot bones similar to those of "Lucy" dating from 3 million to 3.4 million years were also found 60 kilometres away from the site.
The findings were described today in the journal Nature.