Members of the phylum Echinodermata, sea urchins belong to the same taxonomic group as sea stars, sand dollars, sea lilies and sea cucumbers. The barbed creatures possess five bands of pores through which they can extend their tubular feet, and from nodules on their tests, movable spines arise. Between the spines are small, pincer-like organs called pedicellariae, which they use to clean and defend themselves. Although sea urchins generally use their feet to cling to hard surfaces, they can move fast if needed by means of their feet or spines.