Pliocene Hominid Research Articles

New discoveries of pliocene hominids and artifacts in Hadar: International Afar Research Expedition to Ethiopia (fourth and fifth field seasons, 1975–1977)

This note enumerates the paleontological discoveries of the Afar Expedition in 1975–1977.

Laetoli Pliocene hominid footprints and bipedalism

The ability to stand upright and walk on two legs is widely recognized as a crucial hominid adaptation that had profound effects on the course of human evolution. The relief of the upper limb from the task of supporting the trunk in locomotion would have permitted the efficient carriage of food, infants and later tools and weapons. Any or all of these activities could, it is believed, have improved the differential survival of early hominids. Precisely when upright stance and bipedal gait were first acquired within the hominid evolutionary line is not known, and so the discovery of apparently bipedal footprints of Pliocene age at site G, Laetoli, Tanzania is important in itself1,2. A study of the footprints, reported here, has shown that when these hominids walked, they transmitted their body weight and the forces of propulsion to the ground in a manner very similar to that of modern man.

Cladometric analysis of Pliocene hominids

Abstract Quantification of individual crown features allows maximization of information retrieval from isolated hominid molars. The Lukeino specimen demonstrates phenetic affinity to Pan; the Lothagam fossil appears closer to a hypothetical ancestral hominid morphotype than the Laetolil specimens. Consideration of 41 metric features in a cladistic framework establishes Australopithecus afarensis as the sister taxon of Homo and of later australopithecines.

A systematic assessment of early African hominids.

A large sample of Pliocene fossil hominid remains has been recovered from the African sites of Hadar in Ethiopia and Laetolil in Tanzania. These collections, dating approximately between 2.9 and 3.8 million years ago, constitute the earliest substantial record of the family Hominidae. This article assesses the phylogenetic relationships of the newly discovered fossil hominids and provides a taxonomy consistent with that assessment. A new taxon, Australopithecus afarensis, has been created to accommodate these Pliocene hominid fossils.