The extracolumella (in red) is present in all amphisbaenians except Blanus and Bipes. It is a rod-shaped cartilaginous or bony structure that extends from the columella of the stapes to tie into dermal thickenings along the jaw. The extracolumella functions in transmitting aerial sounds or other low-displacement vibrations from the anterior cheek surface to the inner ear. This allows amphisbaenians to detect the subterranean vibrations of their prey.