Olduvai hominid sequence. Schematic representation of the lower half of the Olduvai sequence, showing the approximate vertical position of hominid fossils (numerals enclosed in squares). The potassium-argon dates are indicated near the left margin (m = million years).
Crown areas and length/breadth index. Ranges of size and shape of mandibular teeth in the H. habilis from Bed I and the hominine from lower Bed II compared with those of Australopithecus africanus. Left: crown areas (mm sq.). Right: the length of the tooth expressed as a percentage of the breadth. The cheek teeth (premolars and molars) of the hominines have higher indices because they are elongated and lack the characteristic australopithecine bro
Peninj jaw. Two views of the lower jawbone and teeth of a large-toothed australopithecine from Peninj, next to Lake Natron, some 80 km northeast of Olduvai Gorge. The very small front teeth (incisors and canines) and very large cheek teeth (premolars and molars) characteristic of the robust australopithecine are well shown. This mandible represents a Middle Pleistocene survivor of the African australopithecines, probably a late member of the Olduva