Lucy: forty percent of a skeleton, all the proof of upright walking
A find in Ethiopia, named for a Beatles song playing at camp
Quick facts
- Found
- 24 November 1974, Hadar, Ethiopia
- Completeness
- About 40% of one skeleton (47 fragments)
- Age
- About 3.2 million years (precisely, just under 3.18 million)
- Named for
- The Beatles' 'Lucy in the Sky with Diamonds,' played at camp that night
What happened
On 24 November 1974, at the site of Hadar in Ethiopia, Donald Johanson and his student Tom Gray, working within an expedition that geologist Maurice Taieb helped organize, found a small fossil skeleton later shown to be just under 3.18 million years old. Over two weeks of excavation the team recovered several hundred bone fragments, 47 of which formed a single skeleton representing about 40 percent of one individual, an exceptional proportion for a fossil this old. That night, celebrating at camp while the Beatles' 'Lucy in the Sky with Diamonds' played repeatedly, someone gave the skeleton the name Lucy; its Ethiopian name, Dinkinesh, is Amharic for you are marvelous or you are beautiful, depending on the source. Lucy's thigh bone, pelvis, and vertebrae all show adaptations the Smithsonian and the Institute of Human Origins describe as clear evidence of habitual upright walking, including a pelvis remodeled to balance the trunk over one leg at a time and a spine curved the way a modern human's is.
Why it matters
Lucy became the most famous single fossil in the story of human evolution because she offered something rare: enough of one skeleton, all from one individual, to argue convincingly from the bones themselves that her species walked upright as a matter of course, not as an occasional or debated behavior.
How we know
The Institute of Human Origins at Arizona State University, Donald Johanson's own research institute, gives a detailed account of the discovery date, the naming, and the specific skeletal evidence for bipedalism. The Smithsonian's Human Origins Program independently corroborates the site, age, and bipedal anatomy on two separate pages, though it credits Maurice Taieb alongside Johanson rather than naming Tom Gray, a minor, honestly-noted discrepancy in how different institutions credit the find.
Sources
- Smithsonian Institution. AL 288-1, 'Lucy' (Smithsonian Human Origins Program) (2024) · Reputable sourcehumanorigins.si.edu · The domain "humanorigins.si.edu" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Smithsonian Institution. Australopithecus afarensis (Smithsonian Human Origins Program) (2024) · Reputable sourcehumanorigins.si.edu · The domain "humanorigins.si.edu" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Institute of Human Origins, Arizona State University. About the Fossil Lucy (Institute of Human Origins, Arizona State University) (2024) · Reputable sourceiho.asu.edu · The domain "iho.asu.edu" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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