'Bizarre,' Human-Size Sea Scorpion Found in Ancient Meteorite Crater

About 460 million years ago, a sea scorpion about the size of an adult human swam around in the prehistoric waters that covered modern-day Iowa, likely dining on bivalves and squishy eel-like creatures, a new study finds. The ancient sea scorpions are eurypterids, a type of arthropod that is closely related to modern arachnids and horseshoe crabs. The findings — which include at least 20 specimens — are the oldest eurypterid fossils on record by about 9 million years, said study lead