Fossil range: Carboniferous - Triassic
Listracanthus scale. These scales stood up on the back of the shark, while coarse button-like scales (Petrodus) lay more ventrally.
| Scientific classification
Listracanthus is a genus of extinct cartilaginous fish related to Edestus. They are known primarily from their tremendous, feather-like denticles, which range up to four inches in length. The denticles had a large main spine, with secondary spines emanating from the sides, like 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.
The appearance of these sharks are largely unknown. However, author and illustrator Ray Troll mentions in his book, Sharkabet, about how paleontologist Rainer Zangerl once discovered a large shale slab containing a long, eel-like fish covered in long, spine-like denticles, 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.
- Newberry, J.S. and A.H. Worthen, 1870. Descriptions of fossil vertebrates. Geological Survey of Illinois 4:347-374.