Middle Awash
Encyclopedia
The Middle Awash is an archaeological site
along the Awash River
in Ethiopia
's Afar Depression
. A number of Pleistocene
and late Miocene
hominid
remains have been found at the site, along with some of the oldest known Olduwan
stone artifacts
and patches of fire-baked clay
, disputed evidence of the use of fire. Chimpanzee
and human
lineages are thought to have split around this time, somewhere between 5 million and 7 million years ago.
Sediment
s at the site were originally deposited in lakes or rivers, and carbonate
s found there contain low carbon isotope ratios. This information suggests that, in contrast to the aridity of the current climate, the environment of the Middle Awash during the late Miocene was wet, and the region was occupied by woodland
or grassy woodland habitats. The fossilized remains of vertebrate
s found with the hominids, including the cane rat
, further suggest such an environment. The region was also the site of periodic volcanism
. This rifting probably created distinct ecological
regions inhabited by different species of vertebrate animals.
Important hominid fossils found in the Middle Awash include:
Archaeological site
An archaeological site is a place in which evidence of past activity is preserved , and which has been, or may be, investigated using the discipline of archaeology and represents a part of the archaeological record.Beyond this, the definition and geographical extent of a 'site' can vary widely,...
along the Awash River
Awash River
The Awash is a major river of Ethiopia. Its course is entirely contained within the boundaries of Ethiopia, and empties into a chain of interconnected lakes that begin with Lake Gargori and end with Lake Abbe on the border with Djibouti, some 100 kilometers from the head of the Gulf of Tadjoura...
in 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...
's Afar Depression
Afar Depression
The Afar Triangle is a geological depression that is caused by the Afar Triple Junction which is part of the Great Rift Valley. It overlaps Eritrea, Djibouti and the entire Afar Region of Ethiopia. The Afar Triangle includes the Danakil Depression and the lowest point in Africa, Lake Asal...
. A number of Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
and late Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
hominid
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 ....
remains have been found at the site, along with some of the oldest known Olduwan
Olduwan
The Oldowan, often spelled Olduwan or Oldawan, is the archaeological term used to refer to the stone tool industry that was used by Hominines during the Lower Paleolithic period...
stone artifacts
Artifact (archaeology)
An artifact or artefact is "something made or given shape by man, such as a tool or a work of art, esp an object of archaeological interest"...
and patches of fire-baked clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
, disputed evidence of the use of fire. Chimpanzee
Chimpanzee
Chimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan. The Congo River forms the boundary between the native habitat of the two species:...
and human
Human
Humans are the only living species in the Homo genus...
lineages are thought to have split around this time, somewhere between 5 million and 7 million years ago.
Sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s at the site were originally deposited in lakes or rivers, and carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
s found there contain low carbon isotope ratios. This information suggests that, in contrast to the aridity of the current climate, the environment of the Middle Awash during the late Miocene was wet, and the region was occupied by woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
or grassy woodland habitats. The fossilized remains of vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s found with the hominids, including the cane rat
Cane rat
The genus Thryonomys, also known as cane rats, grass cutters, or cutting grass, is a genus of rodent found throughout Africa south of the Sahara, the only members of the family Thyronomyidae. They are eaten in some African countries and are a pest species on many crops.-Characteristics:Cane rats...
, further suggest such an environment. The region was also the site of periodic volcanism
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
. This rifting probably created distinct ecological
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
regions inhabited by different species of vertebrate animals.
Important hominid fossils found in the Middle Awash include:
- Ardipithecus kadabba
- Ardipithecus ramidus
- Australopithecus afarensisAustralopithecus afarensisAustralopithecus afarensis is an extinct hominid that lived between 3.9 and 2.9 million years ago. A. afarensis was slenderly built, like the younger Australopithecus africanus. It is thought that A...
- Australopithecus garhiAustralopithecus garhiAustralopithecus garhi is a gracile australopithecine species whose fossils were discovered in 1996 by a research team led by Ethiopian paleontologist Berhane Asfaw and Tim White, an American paleontologist. The hominin remains are believed to be a human ancestor species and the final missing link...
- Australopithecus anamensisAustralopithecus anamensisAustralopithecus anamensis is a stem-human species that lived approximately four million years ago. Nearly one hundred fossil specimens are known from Kenya and Ethiopia, representing over 20 individuals.- Discovery :...
- Homo erectusHomo erectusHomo 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...
- Homo sapiens idaltuHomo sapiens idaltuHomo 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"....
found at Herto Bouri.
See also
- List of fossil sites (with link directory)
- List of hominina (hominid) fossils (with images)