[Read the Article]
Fifteen years after its discovery, Ardipithecus ramidus, the oldest known skeleton of a putative human ancestor, was finally unveiled in 11 papers in print and online in October. The discoverers of the 4.4-million-year-old fossil proposed that she was a new kind of hominin, the family that includes humans and our ancestors but not the ancestors of other living apes. They say that Ardi's unusual anatomy was unlike that of living apes or later hominins, such as Lucy. Instead, Ardi reveals the ancient anatomical changes that laid the foundation for upright walking. Not all paleoanthropologists are convinced that Ar. ramidus was our ancestor or even a hominin. But no one disputes the importance of the new evidence.