Artist's reconstruction
***Helicoprion*** is an extinct genus of cartilaginous fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called tooth whorls, which in life were embedded in the lower jaw. As with most extinct cartilaginous fish, the skeleton is mostly unknown. It is one of the most popular sharks of all time. It was always assumed that the *Helicoprion* was a shark, but it is more closely related to ratfish.

Description
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It had skeletons made of cartilage. As a result, the entire body disintegrated once it began to decay, unless preserved by exceptional circumstances. This can make it difficult to draw precise conclusions on the full body appearance of *Helicoprion*.

The tooth was unusual-looking. Many shark fans call the tooth a tooth whorl. The largest known *Helicoprion* tooth whorl, specimen IMNH 49382 representing an unknown species, reached 56 cm (22 in) in diameter and 14 cm (5.5 in) in crown height, which would have belonged to an individual over 7.6 m (25 ft) in length.

### Tooth whorls

*Main article: Tooth whorl*

A **tooth whorl** is a structure found on the *Helicoprion*. Almost all *Helicoprion* specimens are known solely from tooth whorls, which is a name shark lovers call when they see a tooth whorl.

Species
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* *Helicoprion bessonowi* Karpinsky, 1899 (type)
* *Helicoprion davisii* Woodward, 1886
* *Helicoprion ergassaminon* Bendix-Almgreen, 1966

Other material
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Several large whorls are difficult to assign to any particular species group, *H. svalis* among them. IMNH 14095, a specimen from Idaho, appears to be similar to *H. bessonowi*, but it has unique flange-like edges on the apices of its teeth. IMNH 49382, also from Idaho, has the largest known whorl diameter at 56 cm (22 in) for the outermost volution (the only one preserved), but it is incompletely preserved and still partially buried. *H. mexicanus*, named by F.K.G. Müllerreid in 1945, was supposedly distinguished by its tooth ornamentation. 

*Helicoprion* tooth whorl
Its holotype is currently missing, though its morphology was similar to that of IMNH 49382. In 1922, Karpinsky named a new species of *Helicoprion*, *H. ivanovi*, from Gzhelian (latest Carboniferous) strata near Moscow. However, this species has subsequently been removed from *Helicoprion* and placed as a second species of the related eugeneodont *Campyloprion*.

What the tooth whorl looked like
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Hypotheses for the placement and identity of *Helicoprion*'s tooth whorls were controversial from the moment it was discovered. Woodward (1886), who referred the first known *Helicoprion* fossils to *Edestus*, discussed the various hypotheses concerning the nature of *Edestus* fossils.

Karpinsky's hypothesis of the placement of the tooth whorl was putting it on the nose. Many people said that "the tooth whorl on the nose looks so weird." It now has its tooth whorl in its lower jaw.

In popular culture
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*Helicoprion* was a famous animal because it has been found in many websites. People have given it the name **buzzsaw shark**.

Related pages
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* Blabe
* Antliodus
* Chomatodus

Other websites
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* Helicoprion on English Wikipedia
* Sharks portal

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| --- | --- |
| Taxon identifiers | * Wikidata: Q133376
* Wikispecies: Helicoprion
* Fossilworks: 34459
* GBIF: 4825217
* IRMNG: 1059378
* uBio: 4189333
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