The postfrontal is a paired cranial bone found in many tetrapods.
The postfrontal forms part of the rear and upper border of the eye socket when present.
It is particularly large in many extinct amphibians and their sarcopterygian (lobe-finned fish) ancestors, stretching forwards to contact the prefrontal, thus separating the frontal from the rim of the orbit.
In living amphibians (lissamphibians), the postfrontal is absent, having failed to ossify during development.
[1] The postfrontal is present but reduced in some reptiles, including modern squamates (lizards and snakes).