Horseshoe crabs are arthropods that live primarily in and around shallow ocean waters on soft sandy or muddy bottoms. They are more closely related to spiders and scorpions than they are to other crabs.
It is quite possibly the scariest looking creature you might encounter in a shoreline. Horseshoe crab is a prehistoric looking marine creature that has survived since before the time of the dinosaurs. It is a living fossil – forms almost identical to this species were present during the Triassic period 230 million years ago.