The ancient remains of a gigantic marine reptile have been found in southwestern England. Known as an ichthyosaur, the animal lived about 205 million years ago and was up to 85 feet long—almost as big as a blue whale, say the authors of a study describing the fossil published today in PLOS ONE.

Biology textbook have long touted the modern blue whale as the largest animal that ever lived, but this and other fascinating fossil finds hint that there may once have been even bigger creatures swimming Earth’s seas.

Most ichthyosaurs were much smaller than the newly discovered creature—several species in the genus Ichthyosaurus also found in the U.K. were just 5 to 11 feet long. (See a 13-foot-long Jurassic