Leedsichthys are the biggest fish that appeared in the Jurassic Period - and the biggest ever known. It grew to 27 meters long (18 metres in truth, in more modern estimates, 27 metres in the old show estimates - still the largest fish ever even at 18 instead of 27 metres), and sometimes larger, making it the largest bony fish to ever live.

Walking With Dinosaurs

Leedsichthys don't appear in the main series of Walking with Dinosaurs.


A Leedsichthys plays a minor role in Sea Monsters: A Walking with Dinosaurs Trilogy. While visiting the second most dangerous sea, Nigel Marven swims with some Leedsichthys, and watches a Liopleurodon eat one of them. Hybodus and Metriorhynchus are also seen attacking and eating bits off the Leedsichthys.