Elasmosaurus (name meaning "Thin-Plated Lizard") is a genus of plesiosaur that originated during the Late Cretaceous period in what is now North America. A relative of Cryptoclidus measuring 14 meters long and weighing 10 tons, despite much of its length was made of its neck (which consisted of 75 vertebrae), Elasmosaurus was the largest of the Plesiosaurs.

In the Series 2 finale "Fall of a Kingdom: Hell's Aquarium", a small number of Elasmosaurus was brought back from the Cretaceous period of 65 million years ago. They reside in the marine exhibit of the park.


Era & DiscoveryEdit

Elasmosaurus lived in the seas during the Late Cretaceous period 80–65 million years ago. It died out with the dinosaurs and other prehistoric marine reptiles at the end of the Cretaceous.

The first specimen of Elasmosaurus was discovered in 1867 near Fort Wallace, Kansas, and was sent to the American paleontologist Edward Drinker Cope, who named it E. platyurus in 1868. Cope originally reconstructed the skeleton of Elasmosaurus with the skull at the end of the tail, an error which was made light of by the paleontologist Othniel Charles Marsh, and became part of their "Bone Wars" rivalry.

Physical AttributesEdit

Elasmosaurus was one of the largest predators ever to roam the seas of its time and region. They measured 30–50 feet (9–15 m) long and weighed as much as 10 tons (20,000 lbs.), making them larger than their earlier Jurassic cousins Cryptoclidus. In fact, Elasmosaurus was the largest member of the long-necked Plesiosaurs.

Behavior & TraitsEdit

Elasmosaurus lived in huge numbers and were some of the most exciting reptiles ever discovered. Like other plesiosaurs, Elasmosaurus swallowed stones to keep itself from getting buoyant. Being some of the most exciting reptiles ever discovered, Elasmosaurus could save energy, much like dolphins do. 

Their small heads on their long necks were a way to deceive prey. Fish would have been frightened by their big bodies, but what the Elasmosaurus did was, like their ancestors Cryptoclidus, Elsamosaurus used its long neck to sneak their small heads right into the middle a shoal of fish or fish and then catch them with one strike.



  • The sound effects of Elasmosaurus are that of seal, walrus, and whale sound effects.
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