Christopher B Ruff1, Markku Niskanen2. 1. Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, 1830 E. Monument St., Baltimore, MD 21205, USA. Electronic address: cbruff@jhmi.edu. 2. Department of Archeology, University of Oulu, Oulu 90014, Finland. Electronic address: markku.niskanen@oulu.fi.