[1] Florida Atlantic Univ, Dept Anthropol, Boca Raton, FL 33431 USA
[2] Florida Atlantic Univ, Dept Biomed Sci, Boca Raton, FL 33431 USA
[3] Columbia Univ, Dept Anthropol, NY CEP, New York, NY 10027 USA
[4] UCL, Dept Anat & Dev Biol, London WC1E 6BT, England
[5] Natl Museums Kenya, Dept Palaeontol, Nairobi, Kenya