New Australopithecus boisei calvaria from East Lake Turkana, Kenya

Abstract

The calvaria of an adult Australopithecus boisei from Area 104, Koobi Fora, Lake Turkana, is described. The specimen, KNM‐ER 23000, comes from sediments dated to about 1.9 Ma. It consists of the frontal, both parietals, both temporals, most of the occipital as well as two small pieces of sphenoid, and a mandibular tooth root. The specimen is presumed to be an adult male, based on its size and the great development of features associated with the masticatory apparatus. KNM‐ER 23000 is close in general size and shape to KNM‐ER 406, KNM‐ER 13750, and Olduvai Hominid 5 and it has a mixture of features seen in these three roughly contemporaneous crania. The frontal, especially the tori, resembles that of OH 5; the parietals are most like those of KNM‐ER 13750; the occipital is like those of the two other Turkana specimens, and the temporals have a mixture of features from all of these, This specimen adds to our knowledge of variability in A. boisei.