Sand dollars belong to the same group as sea urchins and starfish. They are all radially symmetrical Echinoderms, or spiny skinned animals, with all of their structures accruing in groups of five and arranged in five rays around their center. Sand dollars are delicate round limy wafers from one half to over six inches in diameter, covered with fine dense for of soft brown bristles.
Sand dollars can commonly be found on the lower beaches and shallow sand flats from Maine to Florida, but can also be found on beaches around the world. However, then you find them alive, their shells are covered by short velvety brown spines on which these seemingly motionless creatures can glide along and burrow in the sand. Housed within its shell is a unique animal that few people think about as they gather them.
Sand dollars feed on algae, diatoms, and other minute plant and animal life found among the sand grains on the sea bottom. On the lower shell of the animal, dedicate hairs called cilia sift bits of organic matter from the sand and move it toward its mouth.
