Eurypterid Dossier

Jaekelopterus rhenaniae reconstruction

Common Name Eurypterid
Group Invertebrates
Species Jaekelopterus euryperus
Time Silurian
Diet Carnivore
Temperament Aggressive if approached
XP For Kill 1 XP
PC Release Date April 2, 2016 (v238.0)
Xbox Release Date April 7, 2016 (v733.0)
Tameable No
Rideable No

Found only in the deepest depths of the waters around the island, Eurypterids are dangerous and adaptable Arthropods. As likely to hunt as they are to scavenge, a Eurypterid rarely has difficulty finding food to keep itself nourished, even at the bottom of the ocean.

A Eurypterid’s threat does comes not directly from its raw strength. Instead, it combines a hard defensive exoskeleton with debilitating poison to powerful effect. The sting of a Eurypterid increases torpor while reducing stamina, quickly rendering its opponent unable to defend itself.


While Eurypterid are not intelligent enough to be tamed, This doesn't mean they are without utility for tribes. They are a wonderful source of Chitin, and their digestive tract often contain Silica Pearls. They sometimes even have incredibly rare Black Pearls used for manufacturing mysterious technologies, making them among the most valuable creatures on the island.

— The Dossier

The Jaekelopterus or Eurypterid (Urr-ihp-ter-ihd) is a medium sized carnivorous aquatic invertebrate found in the oceans of the Ark.

Wikipedia has a more detailed and comprehensive article on Eurypterid


Superficially resembles a Pulmonoscorpius with adaptations to fit an aquatic lifestyle. Its rearmost pair of legs are flattened into flippers. Instead of two separate claws, both of the forelimbs work in tandem with formidable spines, closing as a vice to trap and shred prey.


The Eurypterid moves silently along the floor of the ocean, slowly undulating its body to move through the waterways. Since they spawn in clusters of two to four, there will often be many in a single area, often around coral and seaweed. When a player approaches the area to hunt for Silica Pearl clams or for the Eurypterids themselves, the Eurypterids will swim towards the invader and attack. They can poison the player, knocking them out in the depths of the ocean, which will most likely kill them.


  • It was officially revealed by Drake on September 8, 2016.
  • The dossier was revealed by Jat on September 10, 2015.
  • Although it is difficult and there is no purpose for doing so, Eurypterids can be lured to shore where they will strangely swim — almost hovering — in the air. This is most likely a bug.

Trivia not relevant for the game

  • Eurypterids are a broad group with many members. According to the dossier, Ark's Eurypterids are from the genus Jaekelopterus - in real life, these were the largest arthropods ever known to evolve, at 2.5 m (~8 feet) in length.
  • Real life Eurypterids did not bear stingers as the dossier depicts. Most had tails ending in simple points, although some had flattened 'flukes'.
  • Despite appearances, Eurypterids are actually more closely related to horseshoe crabs than scorpions.
  • The dossier mistakenly lists Jaekelopterus as living during the Silurian, when it instead lived during the Devonian.


Gameplay Images



April Fools! ARK Survival Devolved! Plus 'Spotlight Woolly Rhino, Eurypterid, & Dunkleosteus'

April Fools! ARK Survival Devolved! Plus 'Spotlight Woolly Rhino, Eurypterid, & Dunkleosteus'

Spotlight Woolly Rhino, Eurypterid, & Dunkleosteus!

Spotlight Woolly Rhino, Eurypterid, & Dunkleosteus!