Sand dollar
= Sand dollar
{wiki}
A <sand dollar> is a flattened relative of sea urchins within <echinoderms>. Its body form and small spines suit life on or within sediment. The familiar pale disk is the skeleton of an <animal> that was covered by living <tissue>.https://ocean.si.edu/ocean-life/invertebrates/sea-stars-urchins-and-relatives[Smithsonian Ocean, sea urchins and sand dollars]{ref}