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Science & Nature • Paleontology

Helicoprion

Helicoprion is an extinct genus of cartilaginous fish best known from its spiral-shaped tooth whorls.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Helicoprion is an extinct genus of cartilaginous fish best known from its spiral-shaped tooth whorls. Modern studies place the whorl in the lower jaw and indicate that it was adapted for grasping and slicing soft-bodied prey such as cephalopods. The genus is recorded from roughly 290 to 270 million years ago during the Permian.

Description

Helicoprion is known chiefly from fused spiral tooth whorls that appear to have grown continuously during life. These fossils created a long-running puzzle because the rest of the animal is rarely preserved.

Classification

The genus is now generally placed among eugeneodont cartilaginous fishes, with close relationships to the holocephalan lineage that includes modern ratfish and chimaeras. Older reconstructions treated it as a shark, but that view is no longer considered accurate.

Feeding and jaw structure

CT studies and jaw-cartilage specimens show that the tooth whorl sat in the lower jaw and worked as a slicing apparatus. This anatomy is consistent with feeding on soft-bodied animals such as squid-like cephalopods.

Fossil record and distribution

Helicoprion is known from Permian marine deposits in several parts of the world, showing that it had a wide geographic range. The genus is documented across a span of about 20 million years.

Key facts

  • Most fossils attributed to Helicoprion are isolated spiral tooth whorls rather than complete skeletons.
  • CT-based studies indicate the tooth whorl was positioned in the lower jaw.
  • The whorl likely functioned in slicing prey rather than crushing hard shells.
  • Helicoprion fossils are found in marine deposits across multiple continents, indicating a broad distribution.
  • The genus is recorded from roughly 290 to 270 million years ago during the Permian.

Frequently asked questions

What is Helicoprion?
Helicoprion is an extinct genus of cartilaginous fish known mainly from its spiral tooth whorl.
Was Helicoprion a shark?
Older sources described it as a shark, but modern research places it among eugeneodont holocephalans, closer to ratfish and chimaeras.
What did Helicoprion eat?
Evidence suggests it fed on soft-bodied prey, especially cephalopods.
Where have Helicoprion fossils been found?
Fossils are known from marine deposits worldwide, including multiple continents.
How old is Helicoprion?
The genus is known from the Permian, roughly 290 to 270 million years ago.

References

  1. Wikipedia — https://en.wikipedia.org/wiki/Helicoprion
    Supports: General overview, time range, fossil distribution, and jaw placement summary
  2. PubMed — https://pubmed.ncbi.nlm.nih.gov/23445952/
    Supports: CT-based reinterpretation of the spiral tooth whorl and holocephalan affinities
  3. National Geographic — https://www.nationalgeographic.com/science/article/buzzsaw-jaw-helicoprion-was-a-freaky-ratfish
    Supports: Lower-jaw placement, feeding interpretation, and estimated size
  4. Australian Museum — https://www.australian.museum/learn/animals/fishes/helicoprion/
    Supports: Extinct eugeneodont classification, global distribution, and broad evolutionary context
  5. Wikipedia — https://en.wikipedia.org/wiki/Helicoprionidae
    Supports: Family-level classification within eugeneodont holocephalans