Chordata

Chordata is a large group of animals that share key features at some stage of their development, including a notochord (a flexible, rod-like structure along the back), a dorsal nerve cord (a nerve cord running along the back), pharyngeal slits ( openings in the throat area), and a post-anal tail. These traits are present during their embryonic development, and in many, they persist into adulthood. Chordates include diverse animals such as mammals, birds, reptiles, amphibians, fish, and some invertebrates like tunicates and lancelets. They are characterized by their unique body plan that supports complex movement and nervous systems.