The Archaeological Context of the Iwo Eleru Cranium from Nigeria and Preliminary Results of New Morphometric Studies

This is a repository copy of The archaeological context of the Iwo Eleru cranium from Nigeria and preliminary results of new morphometric studies. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/43429/ Book Section: Allsworth-Jones, P., Harvati, K. and Stringer, C. (2010) The archaeological context of the Iwo Eleru cranium from Nigeria and preliminary results of new morphometric studies. In: Allsworth-Jones, P., (ed.) West African Archaeology New developments, new perspectives. BAR, S2164 . Archaeopress , pp. 29-42. ISBN 978 1 4073 0708 4 Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ The archaeological context of the Iwo Eleru cranium from Nigeria and preliminary results of new morphometric studies P. Allsworth-Jones,1 K. Harvati,2 C. Stringer3 1 Department of Archaeology, University of Shefield, Shefield S1 4ET. [email protected] 2 Zentrum für Naturwissenschaftliche Archäologie, Eberhard Karls Universität Tübingen, Rümelinstr. 23, 72070 Tübingen. [email protected] 3 Department of Palaeontology, The Natural History Museum, London SW7 5BD. [email protected] Abstract 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 diocarbonra 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. Signiicant 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 proile 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 t he relatively archaic shape of the vault, and conirm 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. Keywords: Iwo Eleru, Late Stone Age, human cranium, geometric morphometrics The site and the excavations running from south to north, and 16 D-HH running from west to east. Two south-north running trenches were later Iwo Eleru is a rock shelter in south-western Nigeria, 24 added, D 17-27 on the west and S 17-25 on the east. D km north-west of Akure, with coordinates 7°26’30” N and 17-27 (which is particularly important for our purposes) 5°7’40” E (Figure 1). It is 25 km south of the present was interrupted by an unexcavated square D 24 which northern limit of the forest zone. When Thurstan Shaw contained a large fallen roof slab. The section along the irst visited the site, he observed that artefacts indicative of east face of this trench is shown at Figure 3. The total the Late Stone Age were eroding out of the talus slope in number of excavated squares was 810, but for analytical front of the platform, which clearly contained some depth purposes only trenches D and F were used. From the of deposit. It was therefore chosen for excavation to test site as a whole >500,000 artefacts were recovered. The the conlicting hypotheses, either that the forest could not excavators were not able to distinguish distinct layers have been occupied before the introduction of iron tools, as the work proceeded, and the homogeneous deposits or that the occurrence of ground stone axes in presently were therefore divided into arbitrary 15 cm levels. From forested areas implied that it had been so occupied. The trenches D and F, 141 stratigraphic units were therefore excavations were carried out over a four month period in available for analysis, and it is upon this basis that the 1965. As Shaw commented, they succeeded in doing more sequence of events at the site has been constructed. Two than throwing light on those initial questions. photographs of the excavations in progress (taken by Joel Vanderburg) are at Figures 4 and 5. The plan of the site is shown at Figure 2. The rock shelter is formed by the overhang of a huge block of gneiss at Stratigraphy and archaeology the foot of an inselberg. A maximum area of about 7 x 15 metres is within the drip line (which is marked by a dotted In the absence of clearly differentiated natural stratigraphy line on the plan) and the maximum depth of deposit was observed in the ield, the sequence of events at the site was about 1.5 metres. The area to the south of the inselberg determined to a large extent by the statistical analysis of the was laid out in a one-metre grid system, designated by stone artefacts which made up the great bulk of the inds, letters from west to east, and by numbers from south to according to their position within the deined stratigraphic north. Initially, two long trenches were laid out, F 1-26 units. A “time vector plane” accounting for 42.3% of the 29 WEST AFRICAN ARCHAEOLOGY: NEW DEVELOPMENTS, NEW PERSPECTIVES 5˚E 10˚E NIGER Lake Chad Kano BENIN Kaduna 10˚N NIGERIA Ibadan IWO ELERU CAMEROON Lagos Benin City 5˚N Gulf of 0 100 miles Guinea 0 100 kilometres F P I E S N variance was established for the site, and this was divided The only type of pottery deinitely attributed to the LSA is into 8 successive groups which are adequately robust comb stamped ware, as clearly found in situ in trench F 9 and the time directionality of which corresponds with (Shaw and Daniels, 1984, Plate VIII). the radiocarbon dates and the superposition of the units within each column at the site (Shaw and Daniels, 1984, Six samples of charcoal were selected for radiocarbon Fig. 67). At an early stage of the work, the excavators dating, all from trench D, since it was considered that noticed that there was a tendency for the proportion of this showed the least evidence of disturbance, and it also chalcedony versus quartz to decline with depth, hence contained the burial which was located in square D 23. the proportions were carefully noted as work proceeded, The dates as listed are as follows. and the resultant “chalcedony index” was also useful as a stratigraphic check on their interpretation. Combining Lab. No. provenance depth below date BP all the information together, the excavators produced an surface “outline of the Iwo Eleru succession” (Shaw and Daniels, Hv 1512 D 21-22 20-35 cm 3465±65 1984, Table 17) and this has provided the basis for all Hv 1510 D 19-20 50-65 cm 5570±60 further characterisation of this site and its comparison to others. From our point of view, it is important to note that Hv 1509 D 20 65-80 cm 7030±85 there was “little accumulation of deposit in the shelter” Hv 1511 D 18 95-110 cm 8685±120 before it began to be used in the LSA (Shaw and Daniels, 1984: 6). It was used in the recent past by farmers lighting I 1754 D 18 100-115 cm 9150±150 ires in it, hence its name in Yoruba (“Cave of Ashes”). I 1753 D 23 around 70-100 cm 11200±200 Some of the pottery found near the surface may also be burial recent. The bulk of it is “iron age” in type and is likely simply to have become incorporated in the LSA deposits, Shaw commented that this is a “consistent block of dates since no distinctive iron age layer as such was observed. on which considerable reliance can be placed” (Shaw 30 THE ARCHAEOLOGICAL CONTEXT OF THE IWO ELERU CRANIUM FROM NIGERIA F I E S D F F S D XVIIXXVII S D F 31 WEST AFRICAN ARCHAEOLOGY: NEW DEVELOPMENTS, NEW PERSPECTIVES F I E J V F I E J V 32 THE ARCHAEOLOGICAL CONTEXT OF THE IWO ELERU CRANIUM FROM NIGERIA and Daniels, 1984: 7).

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