Australopithecus was a slender four-footer, weighing under 100 pounds. Standing eret, he ran with a swaying side-to-side motion, but walked in a short-stepping plod. His jaw was slightly forward-thrusting, a result of well developed canines and incisors.
Advanced Australopithecus: Distinguished from the early australopithicenes by his increased canial capacity, advanced Australopithecus was a contemporary of Paranthropus. Primitive tools have been found with both, but whether one or the other or both produced them remains unsettled; and Homo Erectus:The first man of our genus, homo erectus is modern of limb but more primitive of hand and brain, with a cranial capacity extending only into the lower ra
Australopithecus to Homo erectus. Australopithecus: Ramapithecus and this early form of Australopithecus, the first certain hominid, are seperated by a gap of nine million years. In this time, the prehumans made great advances - they walked upright, lived on the ground and may have used stones in their defense; Paranthropus: though he stood erect and had hominid features, Paranthropus represents an evolutionary dead end in man's ancestry. A vegeta
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).
"African genesis". The story of early man in Africa is told in this chart. Gray bars in the center represent fossil and tool-bearing sites: those on the left are Beds I and II at Olduvai Gorge in East Africa; those on the right side are South African caves. On the left hand edge of the diagram are absolute dates obtained from Beds I and II by the potassium-argon method. South African dates are known only by cross-checking animal fossils there with
Uakari: A baby uakari clings to its mother. Despite their surprising habit of emitting what sounds like hysterical laughter when annoyed, these creatures are reputed to make delightful pets when they are young- so loyal to their owners that if deserted they refuse all food and ultimately pine away. As adults, however, they are less tractable and do not adjust well to captivity.
Gorilla and Homo Skeletons: Comparative skeletons from a macaque monkey (not pictured- on page 82), gorilla and man illustrate the physiological progression from four-footedness through arm-swinging to two-legged walking. The monkey's arms are somewhat shorter than its legs; it can walk with its hands palm down, an impossible feat for a gorilla. On the other hand, the monkey's down-turned shoulder sockets prohibit brachiation in the true sense of
Male baboon: Safe from predators, a male baboon adopts the posture it may keep all night long. Its ischial callosities, or callous pads, bear its weight and permit it to sleep sitting up even on slender branches.