Allia Bay


The Allia Bay is a region on the east side of Lake Turkana 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.

Geography

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. One of its distinct features is the c.4.2 Ma "bone bed", which was likely a channel of the ancestral Omo River.

Findings

All of the specimens were found to be 3.9 to 4.4 million years old and were dated using 3 main methods: argon-argon dating, potassium-argon dating, and magnetostratigraphy. Leakey, Feibel, McDougall, and Walker were involved in the discovery of 12 new specimens, presumed to be a new species within the genus Australopithecus. The new species was thought to be a possible ancestor of Australopithecus afarensis and a sister species of Ardipithecus ramidus. 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. 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
Specimen NumberDateSiteBody PartDiscoverer
KMN-ER 77271982Allia Bay 261-1Left M2J. Kithumbi
KMN-ER 204191988Allia Bay 251Left radiusM. Kyeva
KMN-ER 204201988Allia Bay 261-1Left M2J. Kimengich
KMN-ER 204211988Allia Bay 261-1Right M3Sieving team
KMN-ER 204221988Allia Bay 261-1Left M1Sieving team
KMN-ER 204231988Allia Bay 261-1Left M2Sieving team
KMN-ER 204271988Allia Bay 261-1Left M1Sieving team
KMN-ER 204281988Allia Bay 261-1Left M3Sieving team
KMN-ER 204321988Allia Bay 261-1Left mandible fragment with canine root and P3-4Sieving team
KMN-ER 226831988Allia Bay 261-1Left P4Sieving team
KMN-ER 241481988Allia Bay 261-1Left dm2Sieving team
KMN-ER 302031995Allia Bay 261-1Right I1A. Walker
KMN-ER 302001995Allia Bay 261Left maxilla with M1 3K. 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.