"Ardi" dates to 4.4. million years and may be the oldest human ancestor ever found.
The world's oldest and most complete skeleton of a potential human ancestor -- named "Ardi," short for Ardipithecus ramidus -- has been unveiled by an international team of 47 researchers.
Their unprecedented, 17-year investigation of Ardi is detailed in a special issue of the journal Science.
The 4.4 million-year-old hominid opens up a new chapter on human evolution because "it is as close as we have ever come to finding the last common ancestor of chimpanzees and humans," project co-director Tim White told Discovery News.
"This is not an ordinary fossil," added White, a paleontologist in the University of California at Berkeley's Human Evolution Research Center. "It's not a chimp. It's not a human."
Instead, he said, "It shows us what we used to be."
Placement on the Human History Timeline
The actual last common ancestor of chimps and humans probably lived between five and 10 million years ago, based on genetic and other estimates, so Ardi falls somewhere between this still unknown species and "Lucy," the famous 3.2 million-year-old "ape-man" hominid, also found in Ethiopia, belonging to the genus Australopithecus.