Descent of Man - habilis

	Australopithecus habilis was discovered by Peter Nzube in 1968. This nearly complete, but very badly crushed specimen, constituted the oldest hominid found in Olduvai Gorge, Tanzania and supported the designation of the then controversial species of Homo habilis. Originally some scientists had resisted classification of Homo habilis as a new species, preferring instead to separate specimens into either A. africanus or H. erectus. Though this specimen features characteristics of both species, there are marked differences. Its estimated cranial capacity of 600 cc is the minimum for classification as Homo, but the difficulties of reconstruction may have contributed to the smallish estimation. The species possessed a larger brain than A. africanus or A. boisei, though smaller than Homo erectus from Java and China. The cranial bones are thinner than typical for australopethicenes, and the braincase is wider and shorter. The width of the face approaches A. boisei in breadth, but is not similarly flat. The profile of H. habilis slopes forward, but projects less than A. africanus. Today some scientists believe that there is too great a range of characteristics for habilis to be a single species and have proposed another subspecies within H. habilis. Size: 7 1/4"L, 4 3/4"W, 4 3/4"H Origin: Olduvai Gorge, Tanzania Age: 2.5 million years old
Homo habilis Discovered in 1973, there is still controversy about this specimen's classifications, with some scientists opting to classify it as an Australopithecene, others believing it is a species of Homo. This individual has a small face, small teeth and small brain. The specimen shows similarities with H. rudolfensis, though it is much smaller. Its size is not due to immaturity, as its third molar shows wear. It has been suggested that it may be a female, but even so, its brain size of 510 cc indicated a size difference too great for a case of sexual dimorphism (smaller females) and classification as rudolfensis. Size: 6 3/4"L, 4 1/4"W, 5"H Origin: Koobi, Kenya Age: 1.9 million years old
	H. rudolfensis The classification of this specimen has been a matter of debate since its discovery, with some scientist arguing in favor of Australopithecus, and some in favor of a species of Homo. Originally dated (incorrectly) a million years before habilis, the most current theory holds that though contemporaneous and geographically concurrent with habilis, this specimen is in fact a different species of Homo. This specimen features a 750 cc braincase, too large for Australopithecines, and perhaps even for habilis, and lacks the crests and heavy muscle markings that characterize australopithecine skulls, as well as lacking the brow ridges associated with Homo erectus. Several features differ from other habilis specimens (a longer face, squared upper jaw and short, shallow palate), leading some scientists to conclude that there is too great a range of characteristics within the specimens for them to be a single species. In 1986 Valerii Alexeev proposed another subspecies within Homo, giving this specimen the scientific name Homo rudolfensis. A photograph of this specimen was used on the cover of Leakey and Lewin's book *Origin*. Size: 8 1/8"L, 4 7/8"W, 6 3/8"H Origin: Koobi Fora in Kenya Age: 1.9 to 1.8 million years old

Updated 28.10.2002