Species of Listracanthus are known primarily from their tremendous, feather-like denticles, which range up to four inches in length.

Listracanthus first appeared in late Carboniferous strata in North America, and eventually disappear from the fossil record some time during the Early Triassic.

However, author and illustrator Ray Troll recounts an anecdote in his book, Sharkabet, about how paleontologist Rainer Zangerl reportedly once discovered a large shale slab containing a long, eel-like fish covered in long, spine-like denticles characteristic of the genus, only to have it dry out and crumble into dust.

As such, according to Zangerl's account, Troll reconstructs Listracanthus as resembling a tremendous, fiercely bristled frill shark.

[3] However, other authors have noted that Listracanthus-like denticles have been found associated with the remains of Menaspiformes like Deltoptychius (which do not have eel-like bodies), and have suggested that Listracanthus is a member of this group.