Ardi on EARTH Magazine

Before Lucy: Older hominid Ardi challenges thinking about human evolution

Thu, 05 Jan 2012 06:41:58 -0500

An artist's reconstruction of _Ardipithecus ramidus_. Illustration 2009, J.H. Matternes

Reconstruction of the 'Ardi' skeleton. Illustration 2009, H.J. Matternes

Lucy, the 3.2-million-year-old Australopithecus afarensis fossil, has long been the poster child for early human evolution. But now she’ll have to share the spotlight with an even older hominid. After spending the last 15 years studying an ancient hominid species about the size of a chimpanzee, scientists revealed details about the 4.4-million-year-old Ardipithecus ramidus in a press conference today. Despite the similarity in size, Ardipithecus didn’t look or act like a chimpanzee, which the researchers say suggests that the last common ancestor of chimpanzees and humans was not chimpanzee-like either. As a result, they said, scientists may need to rethink some long-standing ideas about the origins of the human family tree.

Not the oldest hominid

Thu, 05 Jan 2012 06:41:58 -0500

At 4.4 million years old, Ardipithecus ramidus is not the oldest known hominid. In 2002, scientists announced they had discovered a hominid skull from the Sahel region of Chad. Named Sahelanthropus tchadensis, the species dates to about 7 million years ago. And a few years earlier, scientists had announced the discovery of several hominid fossils, including a thigh bone, in Kenya that dated to about 6 million years ago. They named the species Orrorin tugenensis.

The vital statistics

Thu, 05 Jan 2012 06:41:58 -0500

Ardipithecus ramidus was a hominid that lived in Ethiopia’s Afar region 4.4 million years ago. After spending more than a decade studying the species, scientists can now provide a sketch of what the hominid looked like: