THE OCCIPITAL TORUS AND DEVELOPMENTAL AGE OF SANGIRAN-3

Since its discovery in 1938 Sangiran-3 has been considered a juvenile Pithecanthropus (Homo) erectus, and therefore, excluded from studies o f adult H. erectus. Although morphological features align Sangiran-9 w ith X. erectus; its age designation rests on an unconvincing reconstru ction of the occipital torus and lack of sutural fusion. Evaluation of the occipital shows the original reconstruction is faulty and that th e current midline occipital torus is actually the right lateral torus. The new reconstruction of Sangiran-3 results in midline toral morphol ogy and development that is comparable with that in Sangiran-2. Compar ed with juvenile and adult H. ereclus and Homo sapiens Sangiran-3 has three fully developed layers of vault bone with localized hypertrophy oi the outer table into a sagittal keel, bregmatic eminence, and occip ital torus. Sangiran-3's absolute vault thickness is also within the r ange of adult H. erectus. In addition, the coronal suture is fully int erdigitated and sagittal sutural complexity is consistent with adult H . erectus. Sangiran-3's parietal sagittal contours are indistinguishab le from adult H. erectus, whereas sagittal vault contours of juvenile H. erectus are usually more rounded than adults. These features indica te that Sangiran-3 is best considered a young adult H. ereclus and sho uld be included in metric and non-metric analyses of this taxon. (C) 1 997 Academic Press Limited.