More than 50 years after its discovery on Scotland’s Isle of Skye, scientists have unveiled a monster that would make Nessie blush: a 13-foot-long reptile that ruled the seas 170 million years ago.

The fossil, dubbed the Storr Lochs Monster, is a nearly intact skeleton of an ichthyosaur, a family of extinct marine reptiles that lived alongside the dinosaurs. The creatures were the dolphins of their time: fast swimmers with long, narrow snouts and cone-shaped teeth perfect for eating squid and fish.