Sand dollars are burrowing sea urchins found from northern Baja California to Alaska and throughout the Northern Hemisphere, with some species living in and around the Caribbean Sea. They live in subtidal zones in sheltered bays and in the muddy or sandy bottoms of intertidal zones. Off the coast, they can be found in waters as deep as 131 feet.
Sand dollars use their spines on their flattened underside to burrow into sediment. They are often found together on the bottom of the ocean, which is also where they breed via external fertilization. The larvae of the sand dollar has the ability to clone itself when it senses danger.