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Australopithecus afarensis

AAC Catalogue Number: 2004.11.38

Dates: 3.6 – 3.0 million years ago

Geographic Range: East Africa

Anatomical Features: 

  • Evidence of bipedalism indicated by the shift in location of the foramen magnum (where the spine connects to the cranium) from the rear of the skull towards the base of the skull.
  • Australopithecus afarensis also has an arched foot and a non opposable big toe, which are other traits associated with bipedalism.
  • Shorter legs and long arms suggest that they were not efficient walkers and still spent time in trees.
  • Australopithecines still have a high degree of sexual dimorphism.
  • Estimated to have stood at around three and a half to five feet tall (one to one and a half meters tall).
  • Estimated to have weighed around sixty five pounds (thirty kilograms) to around one hundred pounds (forty five kilograms).

Technology Used: Probably used Mode I Tools as well as perishable implements similar to those made by chimpanzees (see for more details about primate tool use).

Diet: Australopithecus afarensis likely ate hard-shelled foods, nuts, tubers, fruits, seeds, roots, and grasses which were possibly supplemented by scavenged meat and termites.  

Other Info: 

  • The famous specimen “Lucy,” a largely complete Australopithecus afarensis skeleton,was found at Hadar, Ethiopia and is dated to 3.2 million years ago.
  • The Laetoli footprints in Tanzania, dating to 3.5 million years ago, are fossilized impressions of footprints left behind as a bipedal hominin walked across volcanic ash. Scholars believe the hominin was likely either Australopithecus afarensis or Kenyathropus platyops.
  • The Dikika’s Child is an even more complete skeleton of Australopithecus afarensis than Lucy found at the site of Dikika in Ethiopia.
  • (See for more information on Australopithecus afarensis)

Remaining Questions: 

  • How much of Australopithecus afarensis’ diet was composed of meat?

Description from Bone Clones:

“3.2 MYA. The Australopithecus afarensis skull “Lucy” was discovered by D. Johanson in 1974 in Hadar, Ethiopia. Although the short stature of this female, only 3 1/2 feet, suggests that she was immature, eruption of the third molar provides evidence that this specimen was mature, and was simply a female representative of a sexually dimorphic species. The jaw shares features with both apes and other early hominids, with the shape showing some similarities to apes, with relatively large front teeth and parallel-sided tooth rows, and the size of the canine teeth being intermediate between apes and hominids who lived later. The cheek teeth are intermediate in size between hominids who lived earlier and those who lived later. The brain of “Lucy” was relatively small and overlapped in size with living apes; however, the shape of the pelvis, along with other characteristics of the postcranial skeleton, indicates that “Lucy” walked upright. At the same time, other characteristics of the limb skeleton indicate that members of this species spent time in the trees. This combination of an ape-sized brain in a hominid adapted to upright walking adds to the evidence that bipedalism occurred before the development of a relatively large brain.”