OH 7
Encyclopedia
OH 7 also nicknamed "Johnny's Child", is the type specimen of Homo habilis
. The fossils were discovered on November 4, 1960 in Olduvai Gorge
, Tanzania
, by Jonathan
and Mary Leakey
. 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 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 363 cc in account of the fact that the fossils belonged to a 12- or 13-year-old male. This was extrapolated by Phillip Tobias 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
, John Napier
, and Phillip Tobias were among the first to extensively study the fossils. The Leakey team and others argued that, due expanded cranial capacity, gnathic
reduction, relatively small post-canine teeth (compared to Paranthropus boisei
), Homo-like pattern of craniofacial development, and a precision grip in the hand fragments (which indicated the ability for tool use), set OH 7 apart as a transitional species between Australopithecus africanus
and Homo erectus
.
The Leakey team announced the new species Homo habilis in the April 1964 issue of Nature
, 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.
Homo habilis
Homo habilis is a species of the genus Homo, which lived from approximately at the beginning of the Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis Homo...
. The fossils were discovered on November 4, 1960 in Olduvai Gorge
Olduvai Gorge
The Olduvai Gorge is a steep-sided ravine in the Great Rift Valley that stretches through eastern Africa. It is in the eastern Serengeti Plains in northern Tanzania and is about long. It is located 45 km from the Laetoli archaeological site...
, Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
, by Jonathan
Jonathan Leakey
Jonathan Harry Erskine Leakey is a businessman and former palaeoanthropologist. He is the first son of famed anthropologists Louis and Mary Leakey....
and Mary Leakey
Mary Leakey
Mary Leakey was a British archaeologist and anthropologist, who discovered the first skull of a fossil ape on Rusinga Island and also a noted robust Australopithecine called Zinjanthropus at Olduvai. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge,...
. 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
Great Apes
Great Apes may refer to*Great apes, species in the biological family Hominidae, including humans, chimpanzees, gorillas, and orangutans*Great Apes , a 1997 novel by Will Self...
. 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 363 cc in account of the fact that the fossils belonged to a 12- or 13-year-old male. This was extrapolated by Phillip Tobias 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 Leakey
Louis Seymour Bazett Leakey was a British archaeologist and naturalist whose work was important in establishing human evolutionary development in Africa. He also played a major role in creating organizations for future research in Africa and for protecting wildlife there...
, John Napier
John Napier (primatologist)
John Russell Napier, MRCS, LRCP, D.Sc. was a British primatologist, paleoathropologist, and physician, who is notable for his work with Homo habilis and OH 7, as well as on human and primate hands/feet...
, and Phillip Tobias were among the first to extensively study the fossils. The Leakey team and others argued that, due expanded cranial capacity, gnathic
Jaw
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 serving to open and close it and is part of the body plan of...
reduction, relatively small post-canine teeth (compared to Paranthropus boisei
Paranthropus boisei
Paranthropus boisei was an early hominin and described as the largest of the Paranthropus species...
), Homo-like pattern of craniofacial development, and a precision grip in the hand fragments (which indicated the ability for tool use), set OH 7 apart as a transitional species between Australopithecus africanus
Australopithecus africanus
Australopithecus africanus was an early hominid, an australopithecine, who lived between 2–3 million years ago in the Pliocene. In common with the older Australopithecus afarensis, A. africanus was slenderly built, or gracile, and was thought to have been a direct ancestor of modern humans. Fossil...
and Homo erectus
Homo erectus
Homo erectus is an extinct species of hominid that lived from the end of the Pliocene epoch to the later Pleistocene, about . The species originated in Africa and spread as far as India, China and Java. There is still disagreement on the subject of the classification, ancestry, and progeny of H...
.
The Leakey team announced the new species Homo habilis in the April 1964 issue of Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
, igniting debate among the anthropology community which lasted through the 1970s. As early as May 1964, Kenneth Oakley
Kenneth Oakley
Kenneth Page Oakley was an English physical anthropologist, palaeontologist and geologist.Oakley, known for his work in the relative dating of fossils by fluorine content, was instrumental in the exposure in the 1950s of the Piltdown Man hoax.Oakley was born and died in Amersham,...
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
Wilfrid Le Gros Clark
Sir Wilfrid Edward Le Gros Clark was a British anatomist surgeon, primatologist and palaeoanthropologist, today best remembered for his contribution to the study of human evolution....
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.
See also
- List of fossil sites (with link directory)
- List of hominina (hominid) fossils (with images)