Genus Helicoprion

Have you heard of the shark with swirly teeth? This prehistoric shark is called: “Helicoprion”! It lived in Idaho and during the Cisuralian and Guadalupian time periods. Paleontologist, Svend Erik Bendix-Almgreen, found the odd tooth whorl and thought it was a nautilus. Later studies showed that it was a shark and many wondered where the tooth whorl should be placed on this absurd animal. As seen in this next picture:

Reconstructing Helicoprion

Finally another fossil was found and they took a scan on it and found that it belonged in the chin area. You might ask: “Well where did the enormous swirl go?”. Well, scientists found that it kept growing teeth like modern sharks, but it didn’t lose them so it kept growing in a spiral in it’s skin. Now further studies found that it wasn’t a shark at all: it was a ratfish and is closely related to the chimaera in modern day.

What made it evolve to have such a weird tooth formation?

Did the tooth swirl hurt it’s skin?

Was it a fast swimmer and what was it’s diet?