Name: Elasmosaurus
Time: Late Cretaceous
Locality: Asia (Japan) and North America (Kansas & Saskatchewan)
Size: 46 ft / 14 m long
Elasmosaurus is the longest member of the elasmosaur family, and the longest-known plesiosaur.
It's neck, measuring 26ft./8m., makes up more than half of it's total length of 46 ft./14m. Elasmosaurus' neck had 71 vertebrae, many more than the earliest plesiosaurs which had about 28 neck vertebrae.
This length would have enabled Elasmosaurus to curl it's neck around sidways, making almost 2 full circles on either side of its body. It would have been only half as flexible moving its head up and down.
Dean Conybeare, a nineteenth-century English paleontologist who did much of the initial work on these marine reptiles, described the long-neck plesiosaurs as, "snakes threaded through the bodies of turtles". This description gives you a real sense as to the movements of these marine reptiles.
If Elasmosaurus had swung its neck around underwater while swimming, it would have met with a great deal of resistance from the water. Some paleontologists suggest that these long-necked reptiles paddled along on the surface with their necks held up above the water. When fish or other prey were spotted below the surface, the long neck was plunged into the sea, and the prey snapped up. The modern snake bird has a long neck and hunts in much the same way.
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