Name given to a skeleton of Australopithecus afarensis discovered in 1974 by Donald Johansen and Tom Gray in the Afar Valley of Ethiopia. "Its age is about 3.2 million years. Lucy was an adult female of about 25 years. About 40% of her skeleton was found, and her pelvis, femur (the upper leg bone) and tibia show her to have been bipedal. She was about 107 cm (3'6") tall (small for her species) and about 28 kg (62 lbs) in weight." (