Kingdom Animalia
Phylum Chordata
Class Chondrichthyes
Subclass Holocephali
Order Eugenodontida
Family Helicoprionidae
Genus Helicoprion
1st Species Helicoprion bessonovi
2nd Species Helicoprion davisii
3rd Species Helicoprion ferrieri
4th Species Helicoprion ergasaminion
Other attributes
Time Range 290-250 mya
Location Russia, United States of America, China, Canada, Australia, Mexico, Kazakhstan, Japan
Name Meaning Spiral saw
Physical Dimensions 4-8.8 meters long
Dietary Classification Carnivore

Helicoprion was a helicoprionid eugenodontid fish from the Cisuralian-Early Triassic of Russia, the United States of America, China, Canada, Australia, Mexico, Kazakhstan, and Japan. It was named in 1899 by Alexander Karpinsky. It was a strange eugenodontid notable for its tooth whorl (embedded in its lower jaw), and it was one of the most notable disaster taxa, surviving the cataclysmic extinction event of the Permian.


Helicoprion resembled a shark, with a torpedo-shaped body, triangular pectoral and dorsal fins, a crescent-shaped caudal fin, a mid-sized head with a pointy, conical nose and large jaws. However, it had one major defining characteristic: its curved jaws had only one linear row of teeth; as well as this, its lower jaw was more curved than its upper jaw, which gave it the appearance of a buzz-saw. Its body would have been covered in scaly skin.


Helicoprion was a predator, preying on soft-bodied cephalopods. Its tooth whorl had teeth designed for getting a hold of prey, as well as slicing their flesh.


For a while, people did not know what Helicoprion's tooth whorl looked like; first, it was thought to be like a prehensile lash, before being hypothesized to be like a circular saw situated on the tip of a long upper jaw. However, those 2 reconstructions have now been disproved; recent studies (involving the most recent fossil and a CT scanner) have revealed that the whorl would have been situated directly in the lower jaw. As well as this, people did not know how it fed; first, it was thought to have been used as a lash against fish, before being considered to be used as a saw for cutting through the shells of ammonites. Once again, these 2 hypotheses have been disproved, as a look at the fossil whorl confirms that the teeth didn't wear; combined with the fact that it didn't replace worn teeth, it now causes people to speculate that Helicoprion was a specialized predator of soft-bodied mollusks, specifically cephalopods.

In popular cultureEdit

Helicoprion was featured in a special episode of the documentary River Monsters, appearing alongside Xenacanthus, Xiphactinus, Leedsichthys, Megapiranha, Dunkleosteus, and Rhizodus as candidates for the most terrifying prehistoric river dweller. During this episode, Jeremy Wade, the scientist behind the show, researches how its tooth whorl functioned and what it ate; after a while, he rules it off its list due to its non-crushing bite.

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