Ancient specimens shed light on man's evolution

Fossils provide window into period when hominids committed to life on the ground, instead of in the trees

WASHINGTON - Two skeletons of a new hominid species dating back two million years and found in South Africa have shed light on a previously unknown stage in human evolution, studies published Thursday showed.

Baptized Australopithecus sediba, the partially fossilized specimens - an adult female and a juvenile male - were found in good condition in 2008 in a cavern 40 kilometers (24 miles) from Johannesburg.