The Allia Bay is a region on the east side of Lake Turkana [1] in Kenya. The site is known for yielding its first hominid fossils in 1982, with further findings to this day, all of which have been identified as part of Australopithecus anamensis but possibly related to Australopithecus afarensis . Notable people with findings at Allia Bay include: Richard Leakey, Meave Leakey, Craig Feibel, Ian McDougall, Alan Walker. [2]
The geographic coordinates of Allia Bay are 3°35′4″N, 36°16′4″E. As a set of isolate exposures it forms the southernmost region of Koobi Fora. [3] One of its distinct features is the c.4.2 Ma "bone bed", [3] which was likely a channel of the ancestral Omo River. [3]
All of the specimens were found to be 3.9 to 4.4 million years old [2] and were dated using 3 main methods: argon-argon dating, potassium-argon dating, and magnetostratigraphy. [3] Leakey, Feibel, McDougall, and Walker were involved in the discovery of 12 new specimens, presumed to be a new species within the genus Australopithecus . [2] The new species was thought to be a possible ancestor of Australopithecus afarensis and a sister species of Ardipithecus ramidus . [3] The 12 specimens found at Allia Bay were in conjunction with an additional nine that were found at Kanapoi in Kenya; these two sites' findings are the basis of a new, singular species within Australopithecus, for which the first Kanapoi specimen is the holotype, and the later Kanapoi and Allia Bay findings are paratypes. [4] The Allia Bay specimens, listed in the table below, were found in or under the Moiti Tuff and have a mean age of 3.89 million years [3]
| Specimen Number | Date | Site | Body Part | Discoverer |
| KMN-ER 7727 | 1982 | Allia Bay 261-1 | Left M2 | J. Kithumbi |
| KMN-ER 20419 | 1988 | Allia Bay 251 | Left radius | M. Kyeva |
| KMN-ER 20420 | 1988 | Allia Bay 261-1 | Left M2 | J. Kimengich |
| KMN-ER 20421 | 1988 | Allia Bay 261-1 | Right M3 | Sieving team |
| KMN-ER 20422 | 1988 | Allia Bay 261-1 | Left M1 | Sieving team |
| KMN-ER 20423 | 1988 | Allia Bay 261-1 | Left M2 | Sieving team |
| KMN-ER 20427 | 1988 | Allia Bay 261-1 | Left M1 | Sieving team |
| KMN-ER 20428 | 1988 | Allia Bay 261-1 | Left M3 | Sieving team |
| KMN-ER 20432 | 1988 | Allia Bay 261-1 | Left mandible fragment with canine root and P3-4 | Sieving team |
| KMN-ER 22683 | 1988 | Allia Bay 261-1 | Left P4 | Sieving team |
| KMN-ER 24148 | 1988 | Allia Bay 261-1 | Left dm2 | Sieving team |
| KMN-ER 30203 | 1995 | Allia Bay 261-1 | Right I1 | A. Walker |
| KMN-ER 30200 | 1995 | Allia Bay 261 | Left maxilla with M1 3 | K. Kimeu |
The method by which these specimens were named is concurrent with those found at Kanapoi: KNM-ER stands for Kenya National Museum - East Rudolf, where Rudolf is the lesser known, alternative name for Lake Turkana. [3]
Kenyanthropus is a hominin genus identified from the Lomekwi site by Lake Turkana, Kenya, dated to 3.3 to 3.2 million years ago during the Middle Pliocene. It contains one species, K. platyops, but may also include the 2 million year old Homo rudolfensis, or K. rudolfensis. Before its naming in 2001, Australopithecus afarensis was widely regarded as the only australopithecine to exist during the Middle Pliocene, but Kenyanthropus evinces a greater diversity than once acknowledged. Kenyanthropus is most recognisable by an unusually flat face and small teeth for such an early hominin, with values on the extremes or beyond the range of variation for australopithecines in regard to these features. Multiple australopithecine species may have coexisted by foraging for different food items, which may be reason why these apes anatomically differ in features related to chewing.
Australopithecus is a genus of early hominins that existed in Africa during the Pliocene and Early Pleistocene. The genera Homo, Paranthropus, and Kenyanthropus evolved from some Australopithecus species. Australopithecus is a member of the subtribe Australopithecina, which sometimes also includes Ardipithecus, though the term "australopithecine" is sometimes used to refer only to members of Australopithecus. Species include A. garhi, A. africanus, A. sediba, A. afarensis, A. anamensis, A. bahrelghazali and A. deyiremeda. Debate exists as to whether some Australopithecus species should be reclassified into new genera, or if Paranthropus and Kenyanthropus are synonymous with Australopithecus, in part because of the taxonomic inconsistency.
Homo rudolfensis is an extinct species of archaic human from the Early Pleistocene of East Africa about 2 million years ago (mya). Because H. rudolfensis coexisted with several other hominins, it is debated what specimens can be confidently assigned to this species beyond the lectotype skull KNM-ER 1470 and other partial skull aspects. No bodily remains are definitively assigned to H. rudolfensis. Consequently, both its generic classification and validity are debated without any wide consensus, with some recommending the species to actually belong to the genus Australopithecus as A. rudolfensis or Kenyanthropus as K. rudolfensis, or that it is synonymous with the contemporaneous and anatomically similar H. habilis.
Australopithecus afarensis is an extinct species of australopithecine which lived from about 3.9–2.9 million years ago (mya) in the Pliocene of East Africa. The first fossils were discovered in the 1930s, but major fossil finds would not take place until the 1970s. From 1972 to 1977, the International Afar Research Expedition—led by anthropologists Maurice Taieb, Donald Johanson and Yves Coppens—unearthed several hundreds of hominin specimens in Hadar, Ethiopia, the most significant being the exceedingly well-preserved skeleton AL 288-1 ("Lucy") and the site AL 333. Beginning in 1974, Mary Leakey led an expedition into Laetoli, Tanzania, and notably recovered fossil trackways. In 1978, the species was first described, but this was followed by arguments for splitting the wealth of specimens into different species given the wide range of variation which had been attributed to sexual dimorphism. A. afarensis probably descended from A. anamensis and is hypothesised to have given rise to Homo, though the latter is debated.
Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship lines within the family Hominidae, working from biological evidence and cultural evidence.
Anagenesis is the gradual evolution of a species that continues to exist as an interbreeding population. This contrasts with cladogenesis, which occurs when there is branching or splitting, leading to two or more lineages and resulting in separate species. Anagenesis does not always lead to the formation of a new species from an ancestral species. When speciation does occur as different lineages branch off and cease to interbreed, a core group may continue to be defined as the original species. The evolution of this group, without extinction or species selection, is anagenesis.
Australopithecus anamensis is a hominin species that lived approximately between 4.2 and 3.8 million years ago and is the oldest known Australopithecus species, living during the Plio-Pleistocene era.
Paranthropus aethiopicus is an extinct species of robust australopithecine from the Late Pliocene to Early Pleistocene of East Africa about 2.7–2.3 million years ago. However, it is much debated whether or not Paranthropus is an invalid grouping and is synonymous with Australopithecus, so the species is also often classified as Australopithecus aethiopicus. Whatever the case, it is considered to have been the ancestor of the much more robust P. boisei. It is debated if P. aethiopicus should be subsumed under P. boisei, and the terms P. boisei sensu lato and P. boisei sensu stricto can be used to respectively include and exclude P. aethiopicus from P. boisei.
Meave G. Leakey is a British palaeoanthropologist. She works at Stony Brook University and is co-ordinator of Plio-Pleistocene research at the Turkana Basin Institute. She studies early hominid evolution and has done extensive field research in the Turkana Basin. She has Doctor of Philosophy and Doctor of Science degrees.
Australopithecus garhi is a species of australopithecine from the Bouri Formation in the Afar Region of Ethiopia 2.6–2.5 million years ago (mya) during the Early Pleistocene. The first remains were described in 1999 based on several skeletal elements uncovered in the three years preceding. A. garhi was originally considered to have been a direct ancestor to Homo and the human line, but is now thought to have been an offshoot. Like other australopithecines, A. garhi had a brain volume of 450 cc (27 cu in); a jaw which jutted out (prognathism); relatively large molars and premolars; adaptations for both walking on two legs (bipedalism) and grasping while climbing (arboreality); and it is possible that, though unclear if, males were larger than females. One individual, presumed female based on size, may have been 140 cm tall.
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 at Olduvai Gorge,Tanzania and described by her husband Louis a month later. It was originally placed into its own genus as "Zinjanthropus boisei", but is now relegated to Paranthropus along with other robust australopithecines. However, it is also argued that Paranthropus is an invalid grouping and synonymous with Australopithecus, so the species is also often classified as Australopithecus boisei.
Koobi Fora refers primarily to a region around Koobi Fora Ridge, located on the eastern shore of Lake Turkana in the territory of the nomadic Gabbra people. According to the National Museums of Kenya, the name comes from the Gabbra language:
In the language of the Gabbra people who live near the site, the term Koobi Fora means a place of the commiphora and the source of myrrh...
The greater Turkana Basin in East Africa determines a large endorheic basin, a drainage basin with no outflow centered around the north-southwards directed Gregory Rift system in Kenya and southern Ethiopia. The deepest point of the basin is the endorheic Lake Turkana, a brackish soda lake with a very high ecological productivity in the Gregory Rift.
Australopithecus deyiremeda is an extinct species of australopithecine from Woranso–Mille, Afar Region, Ethiopia, about 3.5 to 3.3 million years ago during the Pliocene. Because it is known only from three partial jawbones, it is unclear if these specimens indeed represent a unique species or belong to the much better-known A. afarensis. A. deyiremeda is distinguished by its forward-facing cheek bones and small cheek teeth compared to those of other early hominins. It is unclear if a partial foot specimen exhibiting a dextrous big toe can be assigned to A. deyiremeda. A. deyiremeda lived in a mosaic environment featuring both open grasslands and lake- or riverside forests, and anthropologist Fred Spoor suggests it may have been involved in the Kenyan Lomekwi stone-tool industry typically assigned to Kenyanthropus. A. deyiremeda coexisted with A. afarensis, and they may have exhibited niche partitioning to avoid competing with each other for the same resources, such as by relying on different fallback foods during leaner times.
Kanapoi is a paleontological site in the Kenyan Rift Valley, to the southwest of Lake Turkana. Fossils were first found at Kanapoi in the 1960s by a Harvard expedition, and later by expeditions from the National Museums of Kenya.
Etheria is a genus of freshwater oysters in the Etheriidae family of mollusk bivalves, and a part of the Unionida order. The genus includes a single species, Etheria elliptica, that is found throughout Africa and Madagascar.
Lowarengak is a town in northern Kenya, near the Kenyan-Ethiopian border. Lowarengak lies on the northwestern margin of Lake Turkana, between the towns of Todenyang to the north, and Nachukui to the south. The town receives fresh water from the Lowarengak and Nakitokonon rivers that drain from the Lapur hills.
Francis Harold Brown was an American geologist and geochemist who mapped the sedimentary sequence and geology of most of the Turkana Basin in Kenya, east Africa. Brown introduced single-crystal argon-argon and potassium-argon dating into the Turkana Basin, resolving disputes over the age of Kenyanthropus platyops and other fossils.
The KBS Tuff is an ash layer in East African Rift Valley sediments, derived from a volcanic eruption that occurred approximately 1.87 million years ago (Ma). The tuff is widely distributed geographically, and marks a significant transition between water flow and associated environmental conditions around Lake Turkana shortly after 2 Ma.
Emma Mbua is a Kenyan Paleoanthropologist and a curator, who is the first East African woman to work as a paleoanthropologist.