Omo remains
Encyclopedia
The Omo remains are a collection of hominid
bones discovered between 1967 and 1974 at the Kibish
sites near the Omo River
, Omo National Park
in south-western Ethiopia
. The bones were recovered by a scientific team from the Kenya National Museums directed by Richard Leakey
and others. The remains from the Kamoya's Hominid Site (KHS) were called Omo 1 and those from Paul's Hominid Site (PHS) Omo 2. Parts of the fossils are the earliest classified
by Richard Leakey as Homo sapiens. The results of 40Ar/39Ar dating of the geologic tuff
s in 2004 were for the layer below the fossil tuff (Member I - 198 ± 14 ka) and the layer over the fossil tuff (Member III - 104 ± 7 ka). In a 2005 "Nature News" article on the fossils, Nature magazine called Ethiopia the current choice for the "cradle of Homo sapiens".
The two specimens Omo 1 and Omo 2 differ in morphological traits. Omo 2 characteristics indicate more archaic traits. Studies of the postcranial remains of Omo I indicate an overall modern human morphology with a number of primitive features. Omo I and Omo II hominid fossils are from similar stratigraphic levels over Member I. Authors of the new Homo Omo dating say that the "preferred estimate of the age of the Kibish hominids is 195 ± 5 ka," which is also the record earliest date in this category.
The bones, which include two partial skulls, four jaws, a legbone, around two hundred teeth and several other parts, were found between 1967 and 1974. Very limited fauna and a few stone artefacts found at the sites led to "the reliability of the dates and the provenance of the Kibish hominids" being "repeatedly questioned."
About 30 years later, a detailed stratigraphic analysis of the area surrounding the fossils was carried out. This analysis argon-dated the Member I layer to 195 kya and that of Member III to 105 kya. The numerous new lithic records from Members I and III verify tool technology to the Middle Stone Age
. The lower layer (below the fossils) is considerably older than the 160,000-year-old Herto remains
designated Homo sapiens idaltu, thought to have been the earliest human
s. This suggests that, if humans did originate in Africa as is the current hypothesis, then they did not extend beyond there until much later than was previously thought. The rainy conditions at that time, which are known from isotopic ages
on the Kibish Formation corresponding to ages of Mediterranean sapropel
s, suggest increased flow of the Nile River and necessarily increased flow of the Omo River. Climatic conditions after 185 ka were too dry to allow speleothems to grow in the Levant
ine land-bridge inroad Eurasian migration. RAO theory suggests that H. sapiens sapiens evolved alongside other hominids for a considerable period of time before the other hominids became extinct.
In 2008 new bone remains were discovered from Awoke's Hominid Site (AHS). The AHS fossil's tibia
and fibula were unearthed from Member I, the same layer from which the other Omo remains derive.
Hominidae
The Hominidae or include them .), as the term is used here, form a taxonomic family, including four extant genera: chimpanzees , gorillas , humans , and orangutans ....
bones discovered between 1967 and 1974 at the Kibish
Omo Kibish
The Omo Kibish formation is one of several sites within an ancient rocky formation called Kibish. The Kibish outcrop is where excavations by Richard Leakey and others recovered Homo sapiens remains as old as 125,000 years BCE...
sites near the Omo River
Omo River
The Omo River is an important river of southern Ethiopia. Its course is entirely contained within the boundaries of Ethiopia, and empties into Lake Turkana on the border with Kenya...
, Omo National Park
Omo National Park
Omo National Park is one of the National Parks of Ethiopia. Located in the Southern Nations, Nationalities, and Peoples Region on the west bank of the Omo River, the park covers approximately 4,068 square kilometers, about 870 kilometers southwest of Addis Ababa; across the Omo is the Mago National...
in south-western Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
. The bones were recovered by a scientific team from the Kenya National Museums directed by Richard Leakey
Richard Leakey
Richard Erskine Frere Leakey is a politician, paleoanthropologist and conservationist. He is second of the three sons of the archaeologists Louis Leakey and Mary Leakey, and is the younger brother of Colin Leakey...
and others. The remains from the Kamoya's Hominid Site (KHS) were called Omo 1 and those from Paul's Hominid Site (PHS) Omo 2. Parts of the fossils are the earliest classified
Species problem
The species problem or species concept is a mixture of difficult, related questions that often come up when biologists identify species and when they define the word "species"....
by Richard Leakey as Homo sapiens. The results of 40Ar/39Ar dating of the geologic tuff
Tuff
Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...
s in 2004 were for the layer below the fossil tuff (Member I - 198 ± 14 ka) and the layer over the fossil tuff (Member III - 104 ± 7 ka). In a 2005 "Nature News" article on the fossils, Nature magazine called Ethiopia the current choice for the "cradle of Homo sapiens".
The two specimens Omo 1 and Omo 2 differ in morphological traits. Omo 2 characteristics indicate more archaic traits. Studies of the postcranial remains of Omo I indicate an overall modern human morphology with a number of primitive features. Omo I and Omo II hominid fossils are from similar stratigraphic levels over Member I. Authors of the new Homo Omo dating say that the "preferred estimate of the age of the Kibish hominids is 195 ± 5 ka," which is also the record earliest date in this category.
The bones, which include two partial skulls, four jaws, a legbone, around two hundred teeth and several other parts, were found between 1967 and 1974. Very limited fauna and a few stone artefacts found at the sites led to "the reliability of the dates and the provenance of the Kibish hominids" being "repeatedly questioned."
About 30 years later, a detailed stratigraphic analysis of the area surrounding the fossils was carried out. This analysis argon-dated the Member I layer to 195 kya and that of Member III to 105 kya. The numerous new lithic records from Members I and III verify tool technology to the Middle Stone Age
Middle Stone Age
The Middle Stone Age was a period of African Prehistory between Early Stone Age and Late Stone Age. It is generally considered to have begun around 280,000 years ago and ended around 50-25,000 years ago. The beginnings of particular MSA stone tools have their origins as far back as 550-500,000...
. The lower layer (below the fossils) is considerably older than the 160,000-year-old Herto remains
Homo sapiens idaltu
Homo sapiens idaltu is an extinct subspecies of Homo sapiens that lived almost 160,000 years ago in Pleistocene Africa. is from the Saho-Afar word meaning "elder or first born"....
designated Homo sapiens idaltu, thought to have been the earliest human
Human
Humans are the only living species in the Homo genus...
s. This suggests that, if humans did originate in Africa as is the current hypothesis, then they did not extend beyond there until much later than was previously thought. The rainy conditions at that time, which are known from isotopic ages
Radiometric dating
Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...
on the Kibish Formation corresponding to ages of Mediterranean sapropel
Sapropel
Sapropel is a term used in marine geology to describe dark-coloured sediments that are rich in organic matter...
s, suggest increased flow of the Nile River and necessarily increased flow of the Omo River. Climatic conditions after 185 ka were too dry to allow speleothems to grow in the Levant
Levant
The Levant or ) is the geographic region and culture zone of the "eastern Mediterranean littoral between Anatolia and Egypt" . The Levant includes most of modern Lebanon, Syria, Jordan, Israel, the Palestinian territories, and sometimes parts of Turkey and Iraq, and corresponds roughly to the...
ine land-bridge inroad Eurasian migration. RAO theory suggests that H. sapiens sapiens evolved alongside other hominids for a considerable period of time before the other hominids became extinct.
In 2008 new bone remains were discovered from Awoke's Hominid Site (AHS). The AHS fossil's tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
and fibula were unearthed from Member I, the same layer from which the other Omo remains derive.
See also
- LucyLucy (Australopithecus)Lucy is the common name of AL 288-1, several hundred pieces of bone representing about 40% of the skeleton of an individual Australopithecus afarensis. The specimen was discovered in 1974 at Hadar in the Awash Valley of Ethiopia's Afar Depression. Lucy is estimated to have lived 3.2 million years...
- Java ManJava ManJava Man is the name given to fossils discovered in 1891 at Trinil - Ngawi Regency on the banks of the Solo River in East Java, Indonesia, one of the first known specimens of Homo erectus...
- List of fossil sites (with link directory)
- List of human fossils
- Peking ManPeking ManPeking Man , Homo erectus pekinensis, is an example of Homo erectus. A group of fossil specimens was discovered in 1923-27 during excavations at Zhoukoudian near Beijing , China...
