It is as big as a double decker bus - with vertebrae the size of dinner plates and teeth the size of cucumbers. One hundred and fifty million years ago it ruled the deep sea as the Tyrannosaurus Rex of the ocean. Now Norwegian palaeontologists think they've found the largest complete skeleton of a Pliosaurus This monsterous fossil was found on the Arctic Island of Spitsbergen - about 800 miles from the North Pole.