Homo habilis (2.3 to 1.6 million years ago)
Species Description:
Homo habilis has been a controversial species sinceit was first described in the mid-1960s. Originally, many scientists did notaccept its validity, believing that all specimens should be assigned either tothe genus Australopithecus or to Homo erectus. Today, H.habilis is widely accepted as a species.
Some scientists, however, stillbelieve that many of the earliest fossils assigned to H. habilis aretoo fragmented and separated in time for conclusions about their relationshipsor species compositions to be possible. H. habilis specimens withparticularly large features -- brains or teeth, for instance -- are sometimesassigned as Homo rudolfensis.
Homo habilis, "handy man," is so called because ofthe wealth of tools that have been found with its fossils. The average H.habilis brain was considerably larger than the average Australopithecusbrain. The brain shape is also more humanlike. The bulge of Broca's area, essentialfor speech, is visible in one H. habilis brain cast, indicating that thespecies may have been capable of rudimentary speech. The average H. habilisindividual is thought to have been about five feet tall and 100 pounds, althoughfemales may have been smaller.
Fossil Finds: | ||
The Mystery Skull (debated) The mystery of this specimen's identity may never besolved. This cranium is so different from any other specimen that thereis still no consensus about what it really is. The sagittal crest resemblesa common A. boisei trait, but the teeth are too small to be from thatspecies. | ||
Dik-dik Hominid This is a typical hominid fossil specimen, made up ofvery small fragments. The height of this H. habilis individual,estimated at 3 feet 5 inches tall based on arm and leg bone lengths, isvery small for the species. It was most likely a female. | ||
Olduvai George Cattle trampled this specimen before it was found, somuch of the skull was lost. It consists of teeth and skull fragments. | ||
KNM-ER 1470 This is the most complete H. habilis skull known.The brain case is much larger than any australopithecine skull and lacks thelarge brow ridges typical of Homo erectus. Some people call thisspecimen H. rudolfensis. | ||
Evidence of Culture: | ||
Oldowan stone tools These tools, like most others from the same period, weremade by chipping pieces from chunks of volcanic rock to reveal sharp, jaggededges. |
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