Subphylum Urochordata is a class of marine animals, also known as Tunicates, which belong to the Phylum Chordata. These animals are characterized by the presence of a tunic, made up of a tough outer layer of cellulose, which encloses and protects their soft bodies. Synonyms for Subphylum Urochordata include the common sea-squirts, which are found in shallow marine waters all over the world. These organisms are important filter feeders, removing harmful particles and toxins from the oceanic ecosystems they inhabit. They possess a unique anatomy and reproductive system, with a remarkable ability to regenerate lost body parts. Overall, Subphylum Urochordata is a fascinating class of marine animals with diverse ecological functions and impressive adaptability.