FIGURE 1. (Upper part) Surface profiles of buccal lower teeth enamel edges from the hypoconid tip regions of m2s. (Lower part) The on-edge curves corresponding to the surface profiles. 1. S. kirchbergensis BMNH-19841; 2. S. hundsheimensis BMNH-M.19428; 3. S. hemitoechus BMNH-M.36620; 4. C. antiquitatis BMNH-M.89; 5. C. simum BMNH-1967.8.31.2; 6. R. unicornis BMNH-72.739; 7. R. sondaicus NHMD-CN28; 8. D. sumatrensis BMNH-1921.2.8.2; 9. D. bicornis FMNH-945/1960.