OH 7 (Olduvai Hominid № 7), also nicknamed "Johnny's Child", is the

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...

of ''

Homo habilis ''Homo habilis'' ("handy man") is an extinct species of archaic human from the Early Pleistocene of East and South Africa about 2.31 million years ago to 1.65 million years ago (mya). Upon species description in 1964, ''H. habilis'' was highly ...

''. The fossils were discovered on November 4, 1960 in

Olduvai Gorge The Olduvai Gorge or Oldupai Gorge in Tanzania is one of the most important paleoanthropological localities in the world; the many sites exposed by the gorge have proven invaluable in furthering understanding of early human evolution. A steep-si ...

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

, by Jonathan and

Mary Leakey Mary Douglas Leakey, FBA (née Nicol, 6 February 1913 – 9 December 1996) was a British paleoanthropologist who discovered the first fossilised ''Proconsul'' skull, an extinct ape which is now believed to be ancestral to humans. She also disc ...

. The remains are dated to approximately 1.75 million years, and consist of fragmented parts of a lower mandible (which still holds thirteen teeth, as well as unerupted wisdom teeth), an isolated maxillary molar, two parietal bones, and twenty-one finger, hand, and wrist bones. The OH 7 hand is wide, with a large thumb and broad fingertips, similar to that of humans; however, unlike in humans the fingers are relatively long and exhibit chimpanzee-like curvature. Furthermore, the thumb's orientation relative to the other fingers resembles the anatomy of

great apes The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); ''Gorilla'' (the ...

. The parietal bones — a nearly complete left parietal and fragmented right parietal — were used to deduce the cranial capacity of the hominid, which was placed at 663 cc in account of the fact that the fossils belonged to a 12- or 13-year-old male. This was extrapolated by

Phillip Tobias Phillip Vallentine Tobias (14 October 1925 – 7 June 2012) was a South African palaeoanthropologist and Professor Emeritus at the University of the Witwatersrand in Johannesburg. He was best known for his work at South Africa's hominid fossil ...

to 674 cc for the hominid's full adult potential. However, other scientists have estimated the cranial capacity at 590 cc to 710 cc.

Louis Leakey Louis Seymour Bazett Leakey (7 August 1903 – 1 October 1972) was a Kenyan-British palaeoanthropologist and archaeologist whose work was important in demonstrating that humans evolved in Africa, particularly through discoveries made at Olduvai ...

John Napier John Napier of Merchiston (; 1 February 1550 – 4 April 1617), nicknamed Marvellous Merchiston, was a Scottish landowner known as a mathematician, physicist, and astronomer. He was the 8th Laird of Merchiston. His Latinized name was Ioan ...

, and Phillip Tobias were among the first to extensively study the fossils. The Leakey team and others argued that, due expanded cranial capacity,

gnathic The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...

reduction, relatively small post-canine teeth (compared to ''

Paranthropus boisei ''Paranthropus boisei'' is a species of australopithecine from the Early Pleistocene of East Africa about 2.5 to 1.15 million years ago. The holotype specimen, OH 5, was discovered by palaeoanthropologist Mary Leakey in 1959, and described by ...

''), ''Homo''-like pattern of craniofacial development, and a precision grip in the hand fragments (which indicated the ability for

tool use Tool use by animals is a phenomenon in which an animal uses any kind of tool in order to achieve a goal such as acquiring food and water, grooming, defence, communication, recreation or construction. Originally thought to be a skill possessed o ...

), set OH 7 apart as a transitional species between ''

Australopithecus africanus ''Australopithecus africanus'' is an extinct species of australopithecine which lived between about 3.3 and 2.1 million years ago in the Late Pliocene to Early Pleistocene of South Africa. The species has been recovered from Taung, Sterkfontei ...

'' and ''

Homo erectus ''Homo erectus'' (; meaning "upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as '' H. heidelbergensis'' and '' H. antecessor ...

''. The Leakey team announced the new species ''Homo habilis'' in the April 1964 issue of ''

Nature Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...

'', igniting debate among the anthropology community which lasted through the 1970s. As early as May 1964, Kenneth Oakley and Bernard Campbell had raised concerns about the Leakey team's findings with their own publication in ''Nature'', and in July of that same year Sir Wilfrid Le Gros Clark bluntly stated his hope that ''H. habilis'' "will disappear as rapidly as he came." The controversy and bias against the newly named species lead some anthropologists to refer to ''H. habilis'' as ''Australopithecus habilis'' or assign associated fossil remains to other ''Homo'' species, a trend that continued long after Le Gros Clark's death in 1971. Other critics noted that OH 7 was found in a region known to contain ''P. boisei'' fossils, was of an immature individual, and that the differences between ''H. habilis'' and ''P. boisei'' were not enough to warrant a new species. Some believe OH 7 more closely resembles ''A. africanus''.

References

;Footnotes ;Bibliography * * * * * * * *

External links

*{{commonscat-inline, OH 7 Homo habilis fossils Prehistoric Tanzania Fossils of Tanzania

See also

References

External links