Nicknamed ‘The Monster’, the 150 million-year-old leviathan from the Jurassic era was found 1,300 km from the North Pole, on Spitspergen in the Arctic island chain of Svalbard by Norwegian scientists two years ago.

According to expedition team leader Dr Jorn Hurum of the University of Oslo Natural History Museum, the Svalbard specimen is about 20 per cent larger than the previous biggest marine reptile – a massive pliosaur from Australia.

“We have carried out a search of the literature, so we now know that we have the biggest (pliosaur),” said Dr Hurum. “It’s not just arm-waving anymore.”

“The flipper is three metres long with very few parts missing. We have assembled all the bones in our basement and we amazed ourselves – we had never seen it together before,” he added.

Pliosaurs were a short-necked form of plesiosaur, a group of extinct reptiles that lived in the world’s oceans during the age of the dinosaurs.

A pliosaur’s body was teardrop-shaped with two sets of powerful flippers that it used to “fly” or propel itself through the water.

The scientists had to remove tonnes of rock by hand in high winds, fog, rain, freezing temperatures and with the constant threat of attack by polar bears to excavate ‘The Monster’ in 2007, a year after it’s discovery.

The team had recovered the animal’s snout, some teeth, much of the neck and back, the shoulder girdle and a nearly complete flipper.

“The analysis suggests this beast belongs to a previously unknown species. It’s a large one, and has the same bone structure as the previous one we found,” said co-researcher Espen Knutsen.