You probably think horseshoe crabs are crustaceans, but you’d be wrong. They actually aren’t crabs at all, and there’s more about the horseshoe crab that you wouldn’t believe. This weird-looking marine animal survived two mass extinctions and lived in the Ordovician Period. To begin with, the horseshoe crab, one the world’s oldest living creatures, are quite active. This fascinating crab has ten small walking legs under a strong, sturdy exoskeleton, a long spine in the abdomen, and a long pointy