4.4-Million-Year-Old Fossil Brings Huge Surprises About Human Origins

WASHINGTON, DC (WUSA) -- She's not the "Missing Link," but she's awfully close.

Scientists in DC rolled back the clock on human origins, unveiling their research on a 4.4 million year old skeleton of a hominid they've nicknamed Ardi.

They says she helps us answer the basic human question: where did we come from? She's full of surprises for people who thought they understood human evolution.

Researchers found the partial skeleton of the young adult female Ardipithecus Ramidus in the now barren wastes of the Afar Rift in Ethiopia nearly two decades ago. Only now are they ready to tell us what they've learned from her.

"It took years as a consequence of looking at things like the wrist bone to figure it all out, because we've never seen anything like this before," says C Owen Lovejoy, a professor of anthropology at Kent State University.

Ardi is 1.2 million years older and far more primitive than the Australopithecus most of us call Lucy. But Ardi did not drag her knuckles across the ground like a chimpanzee, she stood upright and walked on two feet.

And she evolved not in the savannah, like scientists suspected up until now, but in a verdant valley surrounded by the creatures of the rain forest.

"A porcupine, a mongoose, a bunch of birds," says Tim White, a professor of human evolution and integrative biology and the University of California, Berkeley, pointing out the bones of animals that were found in the same geological layer with Ardi.

One of the most remarkable things about Ardi is her small canines. In apes and in chimpanzees, the canines are huge and long and sharp, for attacking other males and fighting. But Ardi had small canines, apparently because she -- and her male ancestors -- were cooperating with each other.

Working together as a social group: the essence of what it means to be human.

"Ardipithecus tells us that we have been evolving toward what we are today for at least six million years," says Lovejoy.

Researchers have now uncovered even more ancient hominid fossils in the Awash valley, but we're waiting to find out what mysteries they will reveal.