"Thin plate lizard"
14 m (46 ft)
2.2 tons
65,500,000 B.C.
Kansas, United States
Elasmosaurus ischiadicus
Elasmosaurus marshii
Elasmosaurus nobilis
Elasmosaurus orskensis
Elasmosaurus platyurus
Elasmosaurus serdobensis
Elasmosaurus serpentinus
The elasmosaurids were a family of plesiosaurs characterized by longer necks and more stream-lined bodies than other genera in the order. The genus that lends its name to the family is one of the largest and most famous of the plesiosaurs.

Elasmosaurus had no less than seventy-one vertebrae comprising its neck, more than any other known animal, living or dead. This neck, along with its short tail, would have acted as a rudder, helping the animal steer itself in whatever direct it pleased. Contrary to many depictions of Elasmosaurus and its kin, its neck was far too heavy to lift its head far beyond the surface of the water. And as with many other plesiosaurs, Elasmosaurus' paddles were so rigid and adapted for swimming that they would not have been able to drag itself far enough inland to lay eggs. Thus, it probably gave birth to live young like sea snakes and ichthyosaurs.

A famous legend about the first Elasmosaurus skeleton contends that its discoverer, Edward Drinker Cope, misplaced the head of the animal at the end of the tail and a fellow scientist, Othniel Charles Marsh, corrected him, humiliating Cope and sparking a feud between the two known as the "Bone Wars". While Cope did make this error, it was based upon his notion of the animal as being similar to modern lizards--who has short necks and long tails--and the fact that no one had seen a plesiosaur from the Cretaceous or one of Elasmosaurus' scale prior to its discovery. In addition, it was a more senior paleontologist, Joseph Leidy, who set Cope straight on the position of the animal's head, rather than Marsh.

Docudrama Appearances:
Sea Monsters