The first skull of Australopithecus boisei

The discovery of new Australopithecus boisei specimens in Konso, Ethiopia, has extended the known geographical range of A. boisei. It is now clear that A. boisei coexisted with Homo erectus in a mainly dry grassland environment. It seems likely that there was considerable morphological polymorphism and/or polytypism among all early hominids. This would make it unnecessary to divide taxa at species level, paying considerable attention to small morphological differences.