Prognatholiparis, is a monospecific genus of marine ray-finned fish belonging to the family Liparidae, the snailfishes. It only species is Prognatholiparis ptychomandibularis, the wrinkle-jaw snailfish, which is found in the northeastern Pacific Ocean from near Seguam Island in the Aleutian Islands. It occurs at a depth of around 455m (1,493feet). This species grows to a length of 8.8cm (03.5inches) SL.