Listracanthus is a genus of extinct holocephalid closely related to Edestus. Species of Listracanthus are known primarily from their tremendous, feather-like denticles, which range up to four inches in length. The denticles had a large main spine, from which secondary spines emanate from the sides, like the barbs of a feather or a comb. Listracanthus first appeared in late Carboniferous strata in North America, and eventually disappear from the fossil record some time during the Late Triassic, making it one of the longest-lived genera in the family Edestidae.