Scientists Unearth World's Largest Fish The Leedsichthys grew to up to 50 feet in length By Kate Seamons, Newser Staff Posted Aug 26, 2013 11:51 AM CDT 52 comments Comments (animalwarz) (Newser) – As far as discoveries go, this one is pretty astounding on three counts: It came about by chance, expanded our knowledge of "gigantism," and revealed the world's largest fish. As the Observer reports, two geology students spotted pieces of bone amid the rocks in a quarry in England a few years ago. What they had found was a nearly full skeleton of Leedsichthys, a Jurassic era fish that scientists had previously estimated to grow to more than 25 feet in length. After studying it and other remains, scientists now believe the fish could grow more than twice that long—"around 16.5 meters," or 54 feet, reports PhysOrg. The fossil was a pretty amazing find (especially considering the creature's cartilage-rich skeleton didn't fossilize well) and, per the head of the team behind the research, the discovery broadens our understanding of "the process ... known as gigantism." As Professor Jeff Liston of the National Museums of Scotland explains, scientists know the land animals of the time were growing much larger (think Apatosaurus and Brachiosaurus); they can now confirm that "a parallel process occurred in the oceans." What fish does the Leedsichthys steal the "largest" title from? The whale shark, which can grow to about 40 feet.