Lucy is, quite possibly, the most well-known fossil hominid. Discovered by Donald Johanson and Tom Gray in 1974 at Hadar, Ethiopia, Lucy is dated at 3.2 million years old. This specimen, a 40% complete skeleton of an adult female, gave sufficient evidence that A. afarensis was a bipedal species that walked upright. Lucy, scientifically known as AL 288-1, was named after the Beatles song "Lucy in the Sky with Diamonds."