A fossil of Eurypterus remipes, a “sea scorpion” that lived during the Silurian Period (432-418 million years ago) While they averaged about 6 inches long, one large individual has been discovered that was 4.3 feet in length. The largest known species of Eurypterid could reach a monstrous size of 8 feet long.
All Eurypterus possessed paddles which they could use to swim but most likely walked as a primary means of locomotion. They were most likely, exclusively marine animals with their fossils being found in shallow, intertidal environments. Eurypterus is the state fossil of New York.
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