Leedsichthys

Leedsichthys is an extinct genus of pachycormid fish that lived in the oceans of the Middle to Late Jurassic. It was the largest ray-finned fish, and amongst the largest fish known to have ever existed.

The first remains of Leedsichthys were identified in the nineteenth century. Especially important were the finds by the British collector Alfred Nicholson Leeds, after whom the genus was named "Leeds' fish" in 1889. The type species is Leedsichthys problematicus. Leedsichthys fossils have been found in England, France, Germany and Chile. In 1999, based on the Chilean discoveries, a second species was named Leedsichthys notocetes, but this was later shown to be indistinguishable from L. problematicus.