OH 5
Encyclopedia
OH 5 is a fossilized cranium and the holotype
of the species Paranthropus boisei
. It was discovered in Olduvai Gorge
, Tanzania
, by archaeologist
-paleontologist
Mary Leakey
in 1959. Her husband and fellow scientist Louis Leakey
initially classified the hominid as Zinjanthropus boisei and thought that it was an early ancestor of modern humans that lived approximately 2 million years ago. However, this contention was later withdrawn because of its robust australopithecine
features and the discovery of Homo habilis
soon thereafter.
s of extinct mammal
s for the next few years. On the morning of July 17, 1959, Louis felt ill and stayed at camp while Mary went out to Bed I's Frida Leakey Korongo (korongo is Swahili
for gully
; this one was named after Louis's ex-wife). Sometime around 11:00 a.m., she noticed a piece of bone that "seemed to be part of a skull" which had a "hominid look". After dusting some topsoil away and finding "two large teeth set in the curve of a jaw", she drove back to camp exclaiming "I've got him!" They created a pile of stones around the exposed portion of the fossil to protect it from the weather. Active excavation began the following day; they had chosen to wait for photographer Des Bartlett to arrive so that a photographic record of the entire process of removal could be made. A partial cranium was fully unearthed August 6, though it had to be reconstructed from its fragments which were scattered in the scree
.
Once he had examined the cranium, Louis determined it to be subadult, or adolescent, based on its dentition
, and he and Mary began to call it "Dear Boy". He also believed that it was of a species ancestral to modern humans but a member of the subfamily Australopithecinae. In describing the fossilized hominid in his journal, Louis initially considered the classification Titanohomo mirabilis (wonderful Titan-like man), but he eventually dubbed their find Zinjanthropus boisei (East Africa man). Zinj
is an ancient Arabic word for the East African coast; anthropus refers to the fossil's humanlike characteristics; and boisei refers to Charles Boise, who had been making financial contributions to the Leakeys' work since 1948. This classification was eventually revised to Paranthropus boisei, though this remains a matter of contention since the genus Paranthropus
is disputed because of morphological
similarities to Australopithecus
. In either case, OH 5 is the holotype of its species.
, who had been allowed to examine the Leakeys' Olduvai findings before public announcements of their discovery. Louis also wrote "Finding the World's Earliest Man" for the September 1960 issue of National Geographic, estimating the fossil's age to be 600,000 years old. University of California, Berkeley, geochemists
Garniss Curtis and Jack Evernden used potassium-argon dating
to re-assess the site, finding that Olduvai's Bed I was actually about . Such an application of geochronology
was unprecedented; OH 5 became the first hominin to be dated by that method. The same process was used for OH 7
, the holotype of Homo habilis
(handy man).
After the cranium was reconstructed with a model of the absent mandible, contemporaneous newspapers referred to it as "Nutcracker Man" due to the large posterior teeth and jaws which gave it a resemblance to vintage nutcrackers. Phillip Tobias, a colleague of the Leakeys, has also received attribution for this nickname. Primitive tools fashioned out of rocks and bone were excavated at and around Olduvai's Bed I, sometimes called the FLK Zinjanthropus site since the finding of OH 5. Louis initially believed P. boisei to be a direct ancestor of modern humans (as evident from the title of his National Geographic article) and the maker of those tools found near its remains, but he withdrew this idea once he and Mary unearthed Homo habilis – which had a larger brain – in the same area less than two years later. Despite that, OH 5 made the Leakeys famous and brought more attention to the developing field of paleoanthropology
. The cranium was taken to Kenya after its discovery and was there until January 1965 when it was placed on display in the Hall of Man at the National Museum of Tanzania in Dar es Salaam. It remains there as of 2009, still recognized by the name Zinjanthropus, or simply Zinj.
by Randolph E. Schmid, of AOL News and the Huffington Post, it was revealed that "Nutcracker Man didn't eat nuts after all. After a half-century of referring to an ancient pre-human as "Nutcracker Man" because of his large teeth and powerful jaw, scientists now conclude that he actually chewed grasses instead. The study "reminds us that in paleontology, things are not always as they seem," commented Peter Ungar
, chairman of anthropology at the University of Arkansas
. The new report, by Thure E. Cerling
of the University of Utah
and colleagues, is published in Tuesday's edition of the National Academy of Sciences
. Cerling's team analyzed the carbon
in the enamel
of 24 teeth from 22 individuals who lived in East Africa between 1.4 million and 1.9 million years ago. One type of carbon is produced from tree leaves, nuts and fruit, another from grasses and grasslike plants called sedges. It turns out that the early human known as Paranthropus boisei did not eat nuts but dined more heavily on grasses than any other human ancestor or human relative studied to date. Only an extinct species of grass-eating baboon
ate more, they said."
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
of the species Paranthropus boisei
Paranthropus boisei
Paranthropus boisei was an early hominin and described as the largest of the Paranthropus species...
. It was discovered 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 archaeologist
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...
-paleontologist
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
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,...
in 1959. Her husband and fellow scientist 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...
initially classified the hominid as Zinjanthropus boisei and thought that it was an early ancestor of modern humans that lived approximately 2 million years ago. However, this contention was later withdrawn because of its robust australopithecine
Australopithecine
The term australopithecine refers generally to any species in the related genera Australopithecus or Paranthropus. These species occurred in the Plio-Pleistocene era, and were bipedal and dentally similar to humans, but with a brain size not much larger than modern apes, lacking the...
features and the discovery of Homo habilis
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...
soon thereafter.
Discovery
Mary and Louis Leakey had conducted excavations in Tanzania since the 1930s, though most such work was postponed due to the outbreak of World War II. They returned in 1951, finding mostly ancient tools and fossilFossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of extinct mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s for the next few years. On the morning of July 17, 1959, Louis felt ill and stayed at camp while Mary went out to Bed I's Frida Leakey Korongo (korongo is Swahili
Swahili language
Swahili or Kiswahili is a Bantu language spoken by various ethnic groups that inhabit several large stretches of the Mozambique Channel coastline from northern Kenya to northern Mozambique, including the Comoro Islands. It is also spoken by ethnic minority groups in Somalia...
for gully
Gully
A gully is a landform created by running water, eroding sharply into soil, typically on a hillside. Gullies resemble large ditches or small valleys, but are metres to tens of metres in depth and width...
; this one was named after Louis's ex-wife). Sometime around 11:00 a.m., she noticed a piece of bone that "seemed to be part of a skull" which had a "hominid look". After dusting some topsoil away and finding "two large teeth set in the curve of a jaw", she drove back to camp exclaiming "I've got him!" They created a pile of stones around the exposed portion of the fossil to protect it from the weather. Active excavation began the following day; they had chosen to wait for photographer Des Bartlett to arrive so that a photographic record of the entire process of removal could be made. A partial cranium was fully unearthed August 6, though it had to be reconstructed from its fragments which were scattered in the scree
Scree
Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...
.
Once he had examined the cranium, Louis determined it to be subadult, or adolescent, based on its dentition
Dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, the characteristic arrangement, kind, and number of teeth in a given species at a given age...
, and he and Mary began to call it "Dear Boy". He also believed that it was of a species ancestral to modern humans but a member of the subfamily Australopithecinae. In describing the fossilized hominid in his journal, Louis initially considered the classification Titanohomo mirabilis (wonderful Titan-like man), but he eventually dubbed their find Zinjanthropus boisei (East Africa man). Zinj
Zanj
Zanj was a name used by medieval Arab geographers to refer to both a certain portion of the coast of East Africa and its inhabitants, Bantu-speaking peoples called the Zanj...
is an ancient Arabic word for the East African coast; anthropus refers to the fossil's humanlike characteristics; and boisei refers to Charles Boise, who had been making financial contributions to the Leakeys' work since 1948. This classification was eventually revised to Paranthropus boisei, though this remains a matter of contention since the genus Paranthropus
Paranthropus
The robust australopithecines, members of the extinct hominin genus Paranthropus , were bipedal hominids that probably descended from the gracile australopithecine hominids...
is disputed because of morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
similarities to Australopithecus
Australopithecus
Australopithecus is a genus of hominids that is now extinct. From the evidence gathered by palaeontologists and archaeologists, it appears that the Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct...
. In either case, OH 5 is the holotype of its species.
Analysis
Louis wrote "A new fossil skull from Olduvai" for Nature the week following the excavation, detailing the titular find and the "living floor" of Bed I which was replete with fossils of other mammalian fauna. "The Newest Link in Human Evolution: The Discovery by L.S.B. Leakey of Zinjanthropus Boisei", his account of the dig, was published in the January 1960 issue of Current Anthropology. It was annotated by anthropologist Francis Clark HowellFrancis Clark Howell
Francis Clark Howell, generally known as F. Clark Howell was an American anthropologist. He altered the landscape of his discipline irrevocably by adding a broad spectrum of modern sciences to the traditional "stones and bones" approach of the past and is considered the father of modern...
, who had been allowed to examine the Leakeys' Olduvai findings before public announcements of their discovery. Louis also wrote "Finding the World's Earliest Man" for the September 1960 issue of National Geographic, estimating the fossil's age to be 600,000 years old. University of California, Berkeley, geochemists
Geochemistry
The field of geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks, water, and soils, and the cycles of matter and energy that transport the Earth's chemical components in time and space, and...
Garniss Curtis and Jack Evernden used potassium-argon dating
Potassium-argon dating
Potassium–argon dating or K–Ar dating is a radiometric dating method used in geochronology and archeology. It is based on measurement of the product of the radioactive decay of an isotope of potassium into argon . Potassium is a common element found in many materials, such as micas, clay minerals,...
to re-assess the site, finding that Olduvai's Bed I was actually about . Such an application of geochronology
Geochronology
Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...
was unprecedented; OH 5 became the first hominin to be dated by that method. The same process was used for OH 7
OH 7
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 holotype of Homo habilis
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...
(handy man).
After the cranium was reconstructed with a model of the absent mandible, contemporaneous newspapers referred to it as "Nutcracker Man" due to the large posterior teeth and jaws which gave it a resemblance to vintage nutcrackers. Phillip Tobias, a colleague of the Leakeys, has also received attribution for this nickname. Primitive tools fashioned out of rocks and bone were excavated at and around Olduvai's Bed I, sometimes called the FLK Zinjanthropus site since the finding of OH 5. Louis initially believed P. boisei to be a direct ancestor of modern humans (as evident from the title of his National Geographic article) and the maker of those tools found near its remains, but he withdrew this idea once he and Mary unearthed Homo habilis – which had a larger brain – in the same area less than two years later. Despite that, OH 5 made the Leakeys famous and brought more attention to the developing field of paleoanthropology
Paleoanthropology
Paleoanthropology, which combines the disciplines of paleontology and physical anthropology, is the study of ancient humans as found in fossil hominid evidence such as petrifacted bones and footprints.-19th century:...
. The cranium was taken to Kenya after its discovery and was there until January 1965 when it was placed on display in the Hall of Man at the National Museum of Tanzania in Dar es Salaam. It remains there as of 2009, still recognized by the name Zinjanthropus, or simply Zinj.
Debate over diet
In a Tuesday, May 3, 2011, online news story article from Washington, D.C.Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
by Randolph E. Schmid, of AOL News and the Huffington Post, it was revealed that "Nutcracker Man didn't eat nuts after all. After a half-century of referring to an ancient pre-human as "Nutcracker Man" because of his large teeth and powerful jaw, scientists now conclude that he actually chewed grasses instead. The study "reminds us that in paleontology, things are not always as they seem," commented Peter Ungar
Peter Ungar
Peter S. Ungar is an American paleoanthropologist and evolutionary biologist. He is Distinguished Professor and Chairman of Anthropology at the University of Arkansas. Before arriving at Arkansas he taught at the Johns Hopkins School of Medicine and the Duke University Medical Center.Ungar is...
, chairman of anthropology at the University of Arkansas
University of Arkansas
The University of Arkansas is a public, co-educational, land-grant, space-grant, research university. It is classified by the Carnegie Foundation as a research university with very high research activity. It is the flagship campus of the University of Arkansas System and is located in...
. The new report, by Thure E. Cerling
Thure E. Cerling
Thure E. Cerling is a Distinguished Professor of Geology and Geophysics and a Distinguished Professor of Biology at the University of Utah.Cerling’s research interests are primarily focused on the geochemistry processes occurring near the Earth's surface and on the geological record of ecological...
of the University of Utah
University of Utah
The University of Utah, also known as the U or the U of U, is a public, coeducational research university in Salt Lake City, Utah, United States. The university was established in 1850 as the University of Deseret by the General Assembly of the provisional State of Deseret, making it Utah's oldest...
and colleagues, is published in Tuesday's edition of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
. Cerling's team analyzed the carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
in the enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
of 24 teeth from 22 individuals who lived in East Africa between 1.4 million and 1.9 million years ago. One type of carbon is produced from tree leaves, nuts and fruit, another from grasses and grasslike plants called sedges. It turns out that the early human known as Paranthropus boisei did not eat nuts but dined more heavily on grasses than any other human ancestor or human relative studied to date. Only an extinct species of grass-eating baboon
Baboon
Baboons are African and Arabian Old World monkeys belonging to the genus Papio, part of the subfamily Cercopithecinae. There are five species, which are some of the largest non-hominoid members of the primate order; only the mandrill and the drill are larger...
ate more, they said."