Fossil find sheds new light on evolution of humans

A treasure trove of 4.4-million-year-old fossils from the Ethiopian desert is dramatically overturning widely held ideas about the early evolution of humans and how they came to walk upright, researchers reported.

The centrepiece of the diverse collection of primate, animal and plant fossils is the near-complete skeleton of a human ancestor that demonstrates our earliest forebears looked nothing like a chimpanzee or other large primate.

Instead, the findings suggest that the last common ancestor of humans and primates, which existed nearly two million years earlier, was a primitive creature that shared few traits with modern-day members of either group.

The findings, analysed in a large group of studies published on Thursday in the journal Science, also indicate that our ancestors began walking upright in woodlands, not on grassy savannas as previous generations of researchers had speculated.

The discovery of the specimen called Ardipithecus ramidus "is one of the most important discoveries for the study of human evolution", said paleoanthropologist David Pilbeam of Harvard University, who was not involved in the research.