The archaeological context of the Iwo Eleru cranium from Nigeria and preliminary results of new morphometric studies

The Iwo Eleru skeleton was excavated from the rock shelter of this name in 1965 by Thurstan Shaw and his team. This contracted burial was found in a level with Late Stone Age (LSA) artefacts, and a radiocarbon determination on associated charcoal gave an (uncorrected) age of 11,200 ± 200 BP. The excavators went to considerable trouble to satisfy themselves that the specimen was in situ. There is no occupation prior to the LSA and only slight indications of a subsequent “iron age” occupation. Significant human burials have since been excavated elsewhere in West Africa (notably at Shum Laka and Gobero) but Iwo Eleru so far retains its status as the earliest known such burial in the region. The poorly preserved skeleton was of an adult and probably male individual, and the skull was reconstructed and studied by Brothwell. He linked the skull to recent West African populations, but he recognized that its lower vault and frontal profile were unusual. He also supplied cranial data for a Principal Components Analysis performed by Peter Andrews, and noted that this placed the specimen apart from recent African samples. Stringer included the Iwo Eleru cranium in univariate and multivariate (Canonical Variates, Generalised Distance) analyses for his doctoral thesis, completed in 1974. His results highlighted apparent archaic aspects in the specimen in its long and rather low cranial shape, and although modern overall, it also resembled fossils such as Omo Kibish 2 and Ngandong in certain respects. New studies using a primary replica of Brothwell’s reconstruction have now been carried out by Harvati, employing geometric morphometrics to generate PCA, CVA, Procrustes Distance and Minimum Spanning Tree analyses of the specimen. The new morphometric studies establish the relatively archaic shape of the vault, and confirm that this Late Stone Age individual was markedly different from succeeding populations. The results highlight our present relative lack of knowledge concerning the identity of the manufacturers of LSA artefacts in West Africa and other parts of the continent.