Ardi, is the fossilized skeleton of a female Ardipithecus ramidus who lived 4.4 million years agohttp://en.wikipedia.org/wiki/Ardipithecus_ramidus. Ardi is thought to represent a "critical and early part of human evolution," displacing Lucy as the evolutionary missing linkhttp://en.wikipedia.org/wiki/Lucy_%28Australopithecus%29 between chimpanzees or apes, and homo sapienshttp://news.nationalgeographic.com/news/2009/10/091001-ardipithecus-ramidus-ardi-oldest-human-skeleton-fossils.html. On October 1, 2009, the journal Science published a collection of 11 articles detailing a 15-year study of this skeleton, written by 47 authors from 10 countries http://www.time.com/time/health/article/0,8599,1927200,00.html?xid=rss-healthhttp://www.time.com/time/health/article/0,8599,1927200,00.html?xid=rss-health