Phylum Chordata refers to a group of animals characterized by the presence of a notochord, dorsal nerve cord, pharyngeal slits, and a post-anal tail at some point in their life cycle. Common synonyms for this phylum include Chordates, Chordate Animals, or simply Chords. Chordata is one of the most diverse and largest animal phyla, with over 70,000 species recognized around the world. Other synonyms for Chordata include Vertebrates, which refers specifically to animals with a spinal column, and Protochordates, which refers to the more primitive members of the group. Overall, this phylum is an important grouping in the animal kingdom, as Chordates include many of the most well-known and fascinating animals on the planet.