AL 288-1, commonly known as Lucy or Dinkʼinesh (Amharic: ድንቅ ነሽ, romanized: dənkə näš, lit. 'you are marvellous'), is a collection of several hundred pieces of fossilized bone comprising 40% of the skeleton of a female of the hominin species Australopithecus afarensis. It was discovered in 1974 in Ethiopia, at Hadar, a site in the Awash Valley of the Afar Triangle by Donald Johanson, a paleoanthropologist of the Cleveland Museum of Natural History.
Lucy is an early australopithecine and lived around 3.2 million years ago. The skeleton presents a small skull akin to that of non-hominin apes, plus evidence of a walking-gait that was bipedal and upright, akin to that of humans and other hominins—which combination supports the view of human evolution that bipedalism preceded increase in brain size. A 2016 study proposes that Australopithecus afarensis was, at least partly, tree-dwelling, though the extent of this behaviour is debated.
Lucy was named by Pamela Alderman as the namesake of the 1967 song "Lucy in the Sky with Diamonds" by the Beatles, which was played loudly and repeatedly in the expedition camp all evening after the excavation team's first day of work on the Hadar recovery site. After public announcement of the discovery, Lucy captured much international interest, becoming a household name at the time.
Lucy became famous worldwide as the story of her discovery and reconstruction was published by Johanson and Edey. Beginning in 2007, the fossil assembly and associated artefacts were exhibited publicly in an extended six-year tour of the United States; the exhibition was called Lucy's Legacy: The Hidden Treasures of Ethiopia. There was discussion of the risks of damage to the unique fossils, and other museums preferred to display casts of the fossil assembly. The original fossils were returned to Ethiopia in 2013, and subsequent exhibitions have used casts.
In 2024, after 50 years of follow–on research, the scientific community was of consensus that Lucy's species was not the earliest known member of the human family. And contrary to earlier beliefs that her species first walked upright in open savanna grasslands, later evidence suggests they walked and survived in grassy woodlands among deciduous trees. Her species adapted to various habitats over millennia, enduring severe changes in climate. Notably, she (i.e., her species) was not alone in her environment. "We have multiple [hominin] species in the same time period," said Yohannes Haile-Selassie, director of the Institute of Human Origins at Arizona State University.