Fossil hunters have discovered that fierce prehistoric sea monsters apparently used the Arctic Ocean as a migration route to rule the world's oceans at roughly the same time as dinosaurs reigned on land. The discovery is part of a fossil "hat trick" pulled off by paleontologist Hans Larsson and team as part of a 平特五不中 expedition camped on a remote and inhospitable stretch of Melville Island, 1,200 kilometres north of the Arctic Circle.