PBS
Pbs Learning Media: The Transforming Leap, From Four Legs to Two
John Noble Wilford, a "New York Times" science writer, outlines various hypotheses on the origin of bipedalism.
Wikimedia
Wikipedia: Sahelanthropus
An encyclopedia article on the oldest known hominid discusses the features of the fossils that were found, the region in which they were found, and what this means for human evolution.
Wikimedia
Wikipedia: Australopithecus Anamensis
Wikipedia's entry on Australopithecus anamensis. It discusses its scientific classification, age and its posture.
Other
Cartage.org: Australopithecus Afarensis
This essay provides a picture along with brief physical description of one of modern man's earliest ancestors.
Curated OER
Unesco: Tanzania: Ngorongoro Conservation Area
The Ngorongoro Conservation Area spans vast expanses of highland plains, savanna, savanna woodlands and forests. Established in 1959 as a multiple land use area, with wildlife coexisting with semi-nomadic Maasai pastoralists practicing...