Australopithecus anamensis is a species of australopithecine discovered in 1994 by Maeve Leakey in North Kenya. Its name is derived from anam which means "lake" in the local Turkana language .
The fossils (21 in total) include upper and lower jaws, cranial fragments, and the upper and lower parts of a leg bone (tibia). In addition to this, a fragment of humerus that was found 30 years ago at the same site at Kanapoi has now been assigned to this species.
The fossils have been dated at 3.9 to 4.2 million years old. The dentition is less apelike. The tibial fossil implies that A. anamensis was larger than A. afarensis and Ardipithecus ramidus, with an estimated weight of 46 to 55 kilograms, although it may merely be a large individual of the species. The humanlike anatomy of A. anamensis implies that it was bipedal in posture and locomotion. The discovery of this species pushed bipedal walking back half a million years earlier than the prior dates for A. afarensis.
Facial structure resembles A. afarensis in its apelike appearance. It is felt that Australopithecus anamensis could possibly be an ancestor to "Lucy" (A. afarensis) and counterparts.