Dating early hominids Credit card free online casual encounter
Scouring the dry washes encircling an Ethiopian site where scientists seven years ago found fossils of 4.4 million-year-old human ancestors, University of California, Berkeley, graduate student Yohannes Haile-Selassie has found even older fossils that show human ancestors walked on two legs as early as 5.2 million years ago.
The fossils are the earliest hominid known, and date from close to the time when human ancestors are believed to have split off from the chimpanzees on the first steps of their evolutionary trip to modern Homo sapiens.
The fragmentary fossils, which include teeth, a jawbone, hand, arm and collar bones, and one toe bone, appear to be family members of the species discovered in 1994 by an international team led by UC Berkeley paleoanthropologist Tim White.
They named that species Ardipithicus ramidus, and concluded that it was the earliest known human ancestor.
The toe bone "is consistent with an early form of terrestrial bipedality," Haile-Selassie concluded in his Nature paper.
"These canine teeth are not of humans, but no chimp has canine teeth like that either," White said."This is a huge development in African paleoanthropology and a welcome change in the conduct of this science. This is an example of how that has paid off scientifically, for Africa and for Ethiopia." Clark and Howell are professors emeriti of anthropology at UC Berkeley and among the most respected anthropologists working in Africa during the past century.Haile-Selassie found the new fossils along the western margin of the Afar rift in the Middle Awash region of Ethiopia, about 140 miles northeast of the capital Addis Ababa and 25 kilometers from the Aramis site where White's team found A. The fossils came from sites in four different arroyos draining the margin and one closer to the Aramis discoveries."It's definitely a hominid, and proves that the earlier 4.4 million-year-old Ardipithecus ramidus was a hominid, not an ape." Haile-Selassie reported his finds in the July 12 issue of Nature.A second paper in Nature by geologist Giday Woldegabriel of Los Alamos National Laboratory, coauthored by Haile-Selassie, White and others, described the paleoclimate of the area Ardipithecus roamed nearly 6 million years ago.