Wikipedia states "The term sand dollar (also known as a sea cookie or snapper biscuit in New Zealand, or pansy shell in South Africa) refers to species of extremely flattened, burrowing sea urchins." I've always been enchanted by the lines and patterns within the hard white shell. THEN I went to this website link. There is SO much to learn in this world. Isn't it grand? https://www.mnn.com/earth-matters/animals/stories/things-you-dont-know-about-sand-dollars.