A dinosaur-era Davy Jones's locker of large, predatory sea reptiles—including a giant that scientists have nicknamed "the Monster"—has been discovered by fossil hunters on an Arctic island.

The ancient graveyard once lay deep underwater during the Jurassic period, about 200 million to 145 million years ago (take a virtual swim with Jurassic sea monsters).

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 (map of Norway).

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. (See images of the newly found sea monster.)

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.

Black Mud

In addition to the Monster, the researchers uncovered 6 ichthyosaurs and 21 plesiosaurs during a two-week expedition to Spitsbergen in August.