Australopithecus afarensis

***Australopithecus afarensis*** is an extinct hominid. It lived between about 3.85 million years ago and 2.95 million years ago. Its scientific name is abbreviated as ***A. afarensis***.

The species survived for over 900,000 years, which is over four times as long as modern humans have existed. It lived in East Africa, where Ethiopia, Kenya, and Tanzania now are.

_A. afarensis_ is related to _Australopithecus africanus_, which came a bit later (between 3.03 and 2.04 million years ago). However, it may be more closely related to the genus _Homo_ (which includes _Homo sapiens,_ the modern human species).

_Australopithecus_ means ‘southern ape’. The word _afarensis_ is based on the Afar Depression in Ethiopia, where some of the first _A. afarensis_ fossils were found. Together, _Australopithecus afarensis_ means "southern ape from Afar."

_A. afarensis_ fossils proved that human ancestors walked on two feet over three million years ago, before they evolved larger brains.

## Discoveries

Scientists have found many _A. afarensis_ fossils, starting in 1939.

In 1973 in Hadar, Ethiopia, Donald Johanson and his team of paleoanthropologists found a 3.4 million-year-old _A. afarensis_ knee bone. This was the first fossil to show that humanity's ancestors had been bipedal (walking on two legs) for over 3 million years.

Encouraged by this find, Johanson's team returned to Hadar. Eventually they found hundreds of other _A. afarensis_ fossils, including the most famous: Lucy.

### Lucy

_See the main article: Lucy (Australopithecus)_

In 1974 in Ethiopia, Johanson's team found an _A. afarensis_ skeleton that was around 40% complete. They found 47 out of 207 bones, including parts of the arms, legs, spine, ribs, pelvis, lower jaw, and skull fragments. This was one of the most important fossil discoveries in history.

The team nicknamed this skeleton "Lucy." They used this nickname because they repeatedly played the Beatles song _Lucy in the Sky with Diamonds_ in celebration of their discovery.

Lucy was later found to be around 3.2 million years old. She was a full-grown adult, but was only 110 cm (3.6 feet) tall.

### The 'First Family'

In Hadar, Ethiopia in 1975, paleoanthropologists found a group of _A. afarensis_ fossils from nine adults and four children. All had been buried at once. This fossil group showed evidence that _A. afarensis_ lived in small groups, possibly based on family bonds, similar to other apes.

## Description

_A. afarensis_ was similar to slightly later _Australopithecus africanus_. It had a slender build. Its face was apelike. Based on the size of fossil skulls, its brain was about 1/3 the size of the modern human brain. Its arms were long and strong, and its fingers were curved to help it climb trees.

Based on fossil skeletons, scientists can estimate _A. africanus's_ size. Its height ranged from 1 to 1.7 meters (3.3 to 5.6 feet tall). It weighed about 25 to 64 kg (55 to 141 pounds). Females were much shorter and smaller than males.

_A. afarensis_ was bipedal, meaning that it could walk upright. However, it probably still spent a lot of time climbing trees to find food and shelter.

### Diet

Based on analysis of _A. afarensis_ fossil teeth, the species was omnivorous but mostly ate plant-based things like leaves, seeds, roots, and nuts. Their teeth also show that they ate soft, sugar-rich fruits. They may have sometimes eaten insects and small vertebrates like lizards. Based on their tooth size and shape, they could have eaten hard, brittle foods during seasons when fruit did not grow.

## Related pages

- Human evolution
- Extinction
- Lucy (Australopithecus)