The shingle urchin (Colobocentrotus atratus) is a species of sea urchin from the family Echinometridae. It is sometimes commonly referred to as the shingle sea urchin. It is found on wave-swept intertidal shores in the Indo-West Pacific, particularly on the shores of Hawaii. It is usually found on substrata fully exposed to waves and their associated abrasion. They get as big as a soft ball but are rarely found this size. They are usually found in groups. They feed on periwinkle urchins and corralline algae.