New Method Dates Little Foot to Lucy Era, Promises to Revolutionize Fossil Dating

A new technique for dating fossils that promises be a revolution in palaeontology, combined with space-technology, has helped dated 'Little Foot' 3.67 million years old.

Little Foot is a nearly complete skeletal fossil of an Australopithecus promethus found in a South African cave 21 years ago. Efforts at dating the fossil earlier produced dates ranging 2 million to 4 million years. Researchers at Purdue University used an unconventional method to precisely date the fossil to the Lucy era.

The new method involves measuring aluminum - 26 and beryllium-10 in rock. Measuring decay of these two isotopes is produces more accurate results than carbon-14 dating. The measuring was done using equipment originally designed to analyze solar winds.

"It demonstrates that the later hominids, for example, Australopithecus africanus and Paranthropus did not all have to have derived from Australopithecus afarensis. We have only a small number of sites and we tend to base our evolutionary scenarios on the few fossils we have from those sites. This new date is a reminder that there could well have been many species of Australopithecus extending over a much wider area of Africa," said Ronald Clarke, University of the Witwatersrand, who discovered the Little Foot skeleton.

Researchers also dated stone tools found in another portion of the cave. They concluded the tools are among the oldest known in existence, dating 2.18 million years.