The ancient graveyard once lay deep underwater during the Jurassic period, about 200 million to 145 million years ago The site now sits on the island of Spitsbergen, part of the Norwegian-owned Svalbard archipelago, which lies about 600 miles (966 kilometers) from the North Pole.

In total, 28 well-preserved skeletons of marine reptiles that lived some 150 million years ago have been identified at the site, reports a team from the University of Oslo Natural History Museum in Norway. The fossil haul includes the Monster, an estimated 33-foot-long (10-meter-long) pliosaur that has not yet been fully excavated. Pliosaurs were the top marine predators during a time when the oceans were teeming with large, meat-eating reptiles.

"It was the T. rex of the ocean," said Jørn Hurum, co-leader of the research team. "It would have eaten everything." So far the team has found the Monster's skull, which measures 6.9 feet (2.1 meters) in length, along with dinner plate-size neck vertebrae and portions of the lower jaw containing teeth as thick as cucumbers. The fossil specimen may represent the largest complete pliosaur ever found, Hurum says.

"It looks very promising, because we've got 6 meters [20 feet] of vertebrae and the skull and part of a flipper, so it's probably complete," Hurum said