Which hominin species is represented by the 3.2-million-year-old fossil skeleton known as Lucy?

Lucy is a 3.2-million-year-old fossil skeleton of Australopithecus afarensis.

Donald Johanson and graduate student Tom Gray discovered Lucy in 1974 at Hadar in Ethiopia’s Afar region. The specimen, catalogued as AL 288-1, is about 40 percent complete and includes parts of the skull, pelvis, limbs, and ribs. Her skeleton provided strong evidence that this early hominin walked upright.

Australopithecus afarensis lived in eastern Africa between roughly 3.9 and 2.9 million years ago. Its anatomy combined human-like and ape-like features: the pelvis and knee indicate habitual bipedal walking, while the small brain and some limb features remained primitive compared with later Homo species.

Lucy was named after the Beatles song “Lucy in the Sky with Diamonds,” which played at the expedition camp after her discovery. She was not the first australopithecine fossil, and she is not considered a direct, fully established ancestor of every later human population.