While hunting for fossils in Ethiopia’s Afar Triangle on November 24, 1974, paleoanthropologist Donald Johanson and graduate student Tom Gray stumbled upon the partial remains of a previously unknown species of ape-like hominid.
After a few hours of scouring the sunbaked ground, they decided to take a detour through a nearby gully for one last look.
There, Johanson spotted what he instantly recognized as a piece of hominid elbow bone protruding from the dirt.
In this regard, Lucy was like nothing the researchers had ever seen.
Anthropologists had often speculated that erect posture had developed as hominids evolved larger brains, but Lucy’s brain was only the size of a grapefruit—roughly as big as a chimpanzee’s.
They found dozens of intact pieces of leg, pelvis, hand and arm bones as well as a lower jawbone, teeth and part of the skull.