Cryptoclidus was an 26 foot, eight ton member of a plesiosaur genus from the Middle Jurassic period (180-145 MYA) English deposits.

Creature attributes[edit | edit source]

Physical appearance and biology[edit | edit source]

At 4[1]-8 meters in length[2] (13[1]-26ft[2]) with a neck 2 meters long[1] and weighting 8 tonns,[2][3] Cryptoclidus was unlike other plesiosaurs because it had a seal-like body plan. This body-type allowed it to haul itself onto land, though they were rather cumbersome on land than in water.[3]


Cryptoclidus had a skin color that was blend of brown and dark gray with black spots and had a white underbelly.

Behaviour and traits[edit | edit source]

Cryptoclidus would come onto land for various reasons. These reasons include to bask in the sun before returning to the water, to rest for the night,[2][3] evade predators, and probably even to breed.

[1] Cryptoclidus would hunt anchovy-sized fish,[1] squid,[1][2] and ammonites,[1] such as Perisphinctes.[2] Because of their body size[1], they were ambush predators,[1][2] though they could have searched soft seabead sediments for crabs, worms, and fish.[1] They were prey for the larger Liopleurodon.

[3] [2][1]

In Walking with... Series[edit | edit source]

A pod of Cryptoclidus on the bank of the shore.

Walking with Dinosaurs[edit | edit source]

Cruel Sea[edit | edit source]

Cryptoclidus was featured in the third episode of WWD. It was a stand-in for Plesiosaurus as a plesiosaur. It lived in a small colony, hunted fish underwater and came ashore at night to escape Liopleurodon.

Gallery[edit | edit source]

Behind the Scenes[edit | edit source]

  • Cryptoclidus couldn't go on land.
  • Long neck Plesiosaurs like Cryptoclidus and short neck Pliosaurs like Liopleurodon are now thought to have flukes on their tails, and not smooth lizard-like tails.
  • Cryptoclidus lived from 166 to 164 million years ago so it would not have been alive 149 million years ago.
  • In Walking With Dinosaurs Short Bites, they were known as Plesiosaurs.

List of appearances[edit | edit source]

Notes and references[edit | edit source]

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