Clypeaster subdepressus (Gray 1825)

Clypeasteroids are considered radially symmetrical. The bony ossicles of this species fuse together, forming a calcareous, disk-shaped shell or test. The test is covered with short, movable, densely-distributed spines that aid in movement though sand while feeding. The aboral surface bears five conspicuous flower petal-like structures, called petalloids, which are used in respiration. The test color ranges yellow to dark tan. Clypeasteroids live in the sand fields or the shelly sediment in the warm waters of the Caribbean and Atlantic and feed on organic material, including diatoms.

they are also found in yhe gulf of mexico from the fla keys all the way around to texas.have not changed much in millions of years.there are many more spiecies than shown here.