What species does the 3.2-million-year-old fossil 'Lucy' belong to?

The 3.2-million-year-old fossil “Lucy” belongs to the species Australopithecus afarensis. Her scientific catalog number is AL 288-1, and the specimen consists of several hundred bone fragments representing roughly 40% of a female skeleton.

Lucy was discovered on November 24, 1974, at Hadar in Ethiopia’s Afar Triangle by a team including Donald Johanson. Her skeleton combined a small, apelike skull with anatomical evidence of upright, two-legged walking. That combination helped show that habitual bipedalism evolved before the dramatic expansion of the human brain.

Lucy was not Homo sapiens, nor was she a direct modern human ancestor in any simple, settled sense. Australopithecus afarensis lived about 3.9 to 2.9 million years ago, and other hominin species existed alongside it. The name “Lucy” came from the Beatles song “Lucy in the Sky with Diamonds,” which researchers played during the expedition.