Australopithecus afarensis is an extinct species of hominids that lived in East Africa before the genus Homo appeared 2.8 million years ago. The first and most famous fossil is the one the archaeologist Donald Johanson and his team found in Ethiopia, in the Hadar region, in 1974. It consists of half a skeleton of a female individual the team decided to name Lucy, after the Beatles song, because the night of the discovery, the whole camp celebrated listening to “Lucy in the Sky with Diamonds“.
It is a primate which was apparently bipedal because the bones of the pelvis and legs are more like the human bones. They don’t resemble the bones of any ape. Its canines are bigger than ours, its arms are longer than our arms, and its skull, which has a volume of about half a liter, is not much bigger than a chimp’s.
Lucy, in particular, is about 3 million years old, but the dozens of specimens of A. afarensis that researchers have found in Ethiopia, Tanzania and Kenya in the last decades, are known to have lived between 4 and 2.5 million years ago.
The most spectacular discovery related to this hominid species was made by Mary Leakey in 1970 at Laetoli, Tanzania. She found the footprints left by three A. afarensis walking on volcanic ash after an eruption. When the rain covered the ashes, the footprints were preserved and fossilized. The gait of these three individuals leaves no doubt that they were bipedal. A. afarensis is considered to have been an ancestor species of the genus Homo, to which Homo sapiens belongs.