| Named By: | M. C. Coombs in 1979 |
| Time Period: | 23.03-5.33 Ma Miocene |
| Location: | USA |
| Size: | Exact details unavailable |
| Diet: | Herbivore |
| Fossil(s): | Many specimens |
| Classification: | | Chordata | Mammalia | Perissodactyla | Chalicotherioidea | Chalicotheriidae | Schizotheriinae | |
Tylocephalonyx is an extinct dome-headed chalicothere from the Miocene in North America. It may have used its "dome" in the same way as the pachycephalosaurs. Tylocephalonyx is related to the modern horse, rhino, and tapir.