Discovered by two paleontology students in clay pits near Peterborough, the fossil is the largest known fish ever recorded. Identified by experts from the universities of Portsmouth and Glasgow, Leedsichthys problematicus swam the world's oceans some 155 million years ago.
Originally posted by Pisky
Its mentioned in the BBC website too :
Personally, the one I would hate to meet is Lipleurodon. The shot on 'Walking with Dinosaurs' where one burst out of the sea and took an Allosaurus was an amazing piece of CGI.