Ardi, Oldest Human Skeleton, Discovered

Ardi is a small-brained, 110-pound female of the species Ardipithecus ramidus, nicknamed "Ardi." She is the most complete skeleton, out of more than 30 found.

Ardipithecus ramidus walked upright, according to scientists, and her teeth resemble modern human teeth more closely than they do those of a chimpanzee. However, her feet were capable of grasping, so she would have been able to climb trees.

The Oct. 2nd edition of Science focuses on how hominids, which are the earliest human ancestors, evolved from living in trees to walking on two legs. Much of the evidence comes from the Ardipithecus ramidus fossils.

The Ardipithecus ramidus fossil also puts to rest the notion of the "missing link," a chimpanzee-like animal fitting between humans and today's apes. The new evidence suggests that the study of chimpanzee anatomy and behavior is for the most part irrelevant to understanding our development.

The Ardipithecus ramidus remains were first uncovered in 1992, but it took 17 years to piece together the skeleton. The special issue of Science includes 11 total articles: an overview article, three articles that describe the environment Ardi inhabited, five that analyze specific parts of Ardipithecus' anatomy, and two that discuss the implications for human evolution.