This is the left maxilla of Australopithecus anamensis. This fossil was found in the excavation of site 261-1 at Alia Bay, East Turkana.
Although the Allia Bay fossils are slightly younger, they most closely represent those from Kanapoi and are attributed to Australopithecus anamensis. At Allia Bay, most of the hominids were found at the 261-1 site and this specimen KNMER 30745 came from within the excavation itself. This site lies approximately 5 m below the Moiti Tuff, which is dated elsewhere to 3·940·03 Ma.
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Ward C.V. et al Journal of Human Evolution (2001) Morphology of Australopithecus anamensis from Kanapoi and Allia Bay, Kenya 41, 255–368