Australopithecus afarensis may be one of the earliest ancestors of modern humans. Au. afarensis remains have been found in East and Northeast Africa, and demonstrate primitive features, including a relatively small cranial capacity (approximately 415 cc), subnasal prognathism, relatively large incisors, relatively longer arms than legs, and a high degree of sexual dimorphism. Derived features, such as thick enamel, intermediately sized molars, and reduced canines are also hallmarks of Au. afarensis1.

The lower limbs clearly show this species was bipedal, while the upper limb morphology suggests Au. afarensis may have continued to practice some form of arboreality.

The type specimen for Au. afarensis is LH 4, which was found at Laetoli (Tanzania), and dates between 3.7 and 3.4 million years ago. The most famous A. afarensis fossil is AL288-1, or "Lucy", which was found at Hadar (Ethiopia), and dates to 3.2 million years ago.


  1. Klein RG. 2009. The Human Career: Human Biological and Cultural Origins, Third Edition. University Of Chicago Press.