A human relative with diminutive bones dubbed 'Little Foot' may have lived around the same time as another human relative 'Lucy' that existed 3.2 million years ago, researchers have found.
The skeleton named Little Foot is among the oldest hominid skeletons ever dated at 3.67 million years old, according to an advanced dating method.
Little Foot is a rare, nearly complete skeleton of Australopithecus first discovered 21 years ago in a cave at Sterkfontein, in central South Africa.
The new date places Little Foot as an older relative of Lucy, a famous Australopithecus skeleton dated at 3.2 million years old that was found in Ethiopia.
It is thought that Australopithecus is an evolutionary ancestor to humans that lived between 2 million and 4 million years ago, researchers said.
Stone tools found at a different level of the Sterkfontein cave also were dated at 2.18 million years old, making them among the oldest known stone tools in South Africa.
Ronald Clarke, a professor at the University of the Witwatersrand in South Africa who discovered the Little Foot skeleton, said the fossil represents Australopithecus prometheus, a species very different from its contemporary, Australopithecus afarensis, and with more similarities to the Paranthropus lineage.
"It demonstrates that the later hominids, for example, Australopithecus africanus and Paranthropus did not all have to have derived from Australopithecus afarensis," he said.
"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 Clarke.
The research involving scientists from Purdue University, Witwatersrand, the University of New Brunswick, in Canada; and the University of Toulouse, in France, appears in the journal Nature.
