A eurypterid - also known as a sea scorpion - catching the heavily armoured fish, Pteraspis

Sea scorpions

Sea scorpions, or eurypterids, were the largest arthropods the world has ever seen and could grow to 2.5 metres long. They had a pair of pincers, and in some species these too could become very large. Sea scorpions were predators that were in their heyday in the Silurian and Devonian, though they survived into the Permian. The name sea scorpion is something of a misnomer, as they also inhabited freshwater and may have ventured on to land now and then. They are related to scorpions, horseshoe crabs and spiders.

Scientific name: Eurypterida

Rank: Order

Common names:

broad wing

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The following habitats are found across the Sea scorpions distribution range. Find out more about these environments, what it takes to live there and what else inhabits them.


Discover what these behaviours are and how different plants and animals use them.

Additional data source: Animal Diversity Web

When they lived

Discover the other animals and plants that lived during the following geological time periods.

What their world was like

What killed them

Permian mass extinction Permian mass extinction
The Permian mass extinction has been nicknamed The Great Dying, since a staggering 96% of species died out. All life on Earth today is descended from the 4% of species that survived.

Fossil types

Learn more about the other animals and plants that also form these fossils.

Trace fossils Trace fossils
It's not only the actual bodily remains of dead animals and plants that can become fossils. Things created or left behind by animals can also fossilise, such as their footprints, burrows and dung.


  1. Life
  2. Animals
  3. Arthropods
  4. Merostomata
  5. Sea scorpions

BBC News about Sea scorpions