Late Silurian. Fiddlers Green Formation, Phelps Member, Lang’s Quarry, Herkimer County, New York, USA. Euripterids, or “Sea Scorpions” lived over a hundred million years before dinosaurs evolved. They are not directly related to modern scorpions, their closest living descendant is the horseshoe crab, but they had a pair of terrifying pincers much like modern scorpions do. These euripterids are quite small, but some grew up to five feet long. Sea scorpions lived underwater, as most life did during their age. Dry land was still an inhospitable place for any creature who didn’t want to be roasted by the sun’s rays. But some of euripterid’s arthropod relatives would become the first animal colonizers of terra firma, their exoskeletons providing protection from the sun, and a way to keep retain moisture in the dry air.