NEW AUSTRALOPITHECUS-BOISEI CALVARIA FROM EAST LAKE TURKANA, KENYA

The calvaria of an adult Australopithecus boisei from Area 104, Koobi Fora, Lake Turkana, is described. The specimen, KNM-ER 23000, comes fr om sediments dated to about 1.9 Ma. It consists of the frontal, both p arietals, both temporals, most of the occipital as well as two small p ieces of sphenoid, and a mandibular tooth root. The specimen is presum ed to be an adult male, based on its size and the great development of features associated with the masticatory apparatus. KNM-ER 23000 is c lose in general size and shape to KNM-ER 406, KNM-ER 13750, and Olduva i Hominid 5 and it has a mixture of features seen in these three rough ly 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 te mporals have a mixture of features from all of these, This specimen ad ds to our knowledge of variability in A. boisei.