1. Department of Anthropology; University College London; London WC1 E6BT United Kingdom
2. Gashaka Primate Project; Serti 663 001 Taraba State Nigeria
3. Department of Biological Sciences; Taraba State University; Jalingo PMB 1167 Nigeria
4. Leverhulme Trust Early Career Fellow; School of Archaeology, University of Oxford; Dyson Perrins Building, South Parks Road Oxford OX1 3QY United Kingdom