Phylum Echinodermata is a diverse group of marine animals that includes starfish, sea urchins, sand dollars, and sea cucumbers. It's interesting to note that there are several synonyms for the term Echinodermata, including Echinozoa, Echindermata, and Echinoidea. These synonyms are used in different contexts and may have subtle differences in meaning. For example, Echinoidea refers specifically to the class of animals that includes sea urchins and sand dollars, while Echinozoa is a more general term encompassing all Echinoderms. Regardless of the name used, these fascinating creatures are some of the most unique and captivating in the ocean.