Sea-scorpion
Guides
Eurypterida
sea scorpions, eurypterids
Eurypterida is an extinct order of aquatic chelicerate arthropods commonly known as sea scorpions. They ranged from the Cambrian through the Permian periods, with their main diversification occurring during the Paleozoic. The group includes both marine and freshwater species, with body sizes ranging from a few centimeters to over two meters in some species. Eurypterids are characterized by a segmented body with a prosoma and opisthosoma, paired swimming paddles, and a terminal telson spine. They represent one of the largest arthropod groups in the fossil record and are significant for understanding early chelicerate evolution.