That's a shoal of Leedsichthys, and they are the biggest fish that have ever lived.
— Allen, about Leedsichthys
Leedsichthys (name meaning "Leed's Fish") is a genus of Pachycormidae that originated during the Middle Jurassic period in what is now Europe. Measuring 22 meters in length and weighing up to 40 tons, this species of giant ray-finned fish was among the largest creatures in the Jurassic seas, outweighing even the huge pliosaur Liopleurodon.

In the episode "Cruel Jurassic Seas" a number of 4 Leedsichthys were brought back to the park from Late Jurassic 149 million years ago. They reside in the Primeval Aquarium enclosure of the park's marine exhibit.


Era & DiscoveryEdit

Leedsichthys lived during the Late Jurassic period, 155 – 145 million years ago. It shared the waters with Hybodus, Metriorhynchus, Ophthalmosaurus, Cryptoclidus, and Liopleurodon. During the 1880s, the gentleman farmer Alfred Nicholson Leeds collected large fish fossils from loam pits near Peterborough, England. 

Physical AttributesEdit

Leedsichthys was the largest fish that existed in the Jurassic period as well as the largest fish that ever lived. They grew to measure 72 feet (22 m) long and weighing up to 40 tons (80,000 lbs.), making it the largest bony fish to ever live. Despite Leedsichthys' monstrous size, it was not without its predators. LiopleurodonHybodusMetriorhynchus, and other marine carnivores might chance an attack if it is slightly away from the school because the slow Leedsichthys wouldn't attack back.

Behavior & TraitsEdit

Like modern whale sharks and baleen whales, Leedsichthys was a gentle giant that lived on shrimp, jellyfish, fish, plankton, and any small animals floating in the Jurassic ocean. It would have swum slowly through the upper waters of the ocean, taking mouthfuls of plankton-rich water and sieving them through the giant mesh-plates at the back of its mouth.

Its feeding habits were similar to those of modern baleen whales. It was a ray-finned fish, making it a relative of most fish living on Earth today. Leedsichthys also lived in huge shoals. At a certain time of year, the lived on their fat reverse and that really shorted out the healthy fish from the sick ones.


Trivia Edit

  • Leedsichthys is the largest fish to be brought back to the park.
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