New Fossil Ape May Shake Human Family Tree
Editor's note: The original headline for this story—"New Fossil Ape May Shatter Human Evolution Theory"—has been changed to more clearly reflect the implications of the discovery.
Fossil teeth found in Ethiopia might represent a previously unknown species of great ape that lived in Africa ten million years ago, paleontologists report.
The find not only fills an important gap in the fossil record, the Japanese and Ethiopian team says, but could also demolish a working theory of human evolution.
The teeth—eight molars and a canine—come from Ethiopia's fossil-rich Afar region, a valley made famous by the 1974 discovery of the early human ancestor known as Lucy. (What was Lucy?)
For years scientists have been unable to find fossils of direct ancestors of modern great apes in Africa dating back to between 8 million and 14 million years ago.
But the fossil record of great apes—including gorillas, chimpanzees, and bonobos—is abundant in Asia and Europe during this time (see related pictures of an ancient great ape found in Spain).
Experts had speculated that the common ancestor of all apes and humans had left Africa and split off into separate species.
Among the new species was the ancestor of African apes and humans, which returned to Africa sometime around seven million years ago. Molecular analyses of fossils from Europe and later African species seemed to back up this hypothesis.
The recent fossil discovery, however, means that ancient gorilla-like apes lived in Africa as far back as ten million years ago.
"Based on this fossil, that means the split is much earlier than has been anticipated by the molecular evidence," said Berhane Asfaw, a study co-author at the Rift Valley Research Service in the Ethiopian capital of Adis Abeba (Addis Ababa).
"That means everything has to be put back."
Diet Clues
Researchers say that new, ten million-year-old fossils found in Ethiopia, prove that the theory that humans may have evolved from a species of great apes eight million years ago, may not be true, but that humans may have split from apes as long as 10.5 million years ago.

At least nine fossilized teeth, one canine tooth and eight molars, of a previously unknown species of apes found in Africa were discovered by a team of researchers from Ethiopia and Japan who then compared the 3-D make up of the teeth to other fossils that date back as far as 8 million years and found that the fossils are likely a "direct ancestor" of apes currently living in Africa and that the new ape fossils were that of a species of gorilla who ate mostly plants high in fiber.

Current fossils and research say that the evolutionary split from apes to humans occurred at least eight million years ago. The new fossils say that the split may have happened as long as 10.5 million years ago.

"Based on this fossil, that means the split is much earlier than has been anticipated by the molecular evidence. That means everything has to be put back," said researcher at the Rift Valley Research Service in Ethiopia and a co-author of the study, Berhane Asfaw. 

Despite the finds, other researchers are not convinced that the findings are correct.

"It is stretching the evidence to base a time scale for the evolution of the great apes on this new fossil. These structures appear on at least three independent lineages of apes, including gorillas, and they could relate to a dietary shift rather than indicating a new genetic trait," said a Professor at the London Natural History Museum in the United Kingdom, Peter Andrews who also added, "but the fossil evidence for the evolution of our closest living relatives, the great apes, is almost non-existent.

Researchers have named the newly discovered species ''Cororapithecus abyssinicus'' whose remains were found in the Afar Region of Ethiopia, the same place where the remains of Lucy were discovered in 1974.