Chordata
Chordata is a diverse group of animals characterized by the presence of a notochord, a flexible rod-like structure that runs along the length of the body. Other defining features of this group include a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail. Chordates can be found in a wide range of habitats, from the depths of the ocean to the heights of the mountains. This category includes familiar animals such as mammals, birds, reptiles, amphibians, and fish.