Chordata is a phylum of animals that includes vertebrates, such as fish, amphibians, reptiles, birds, and mammals. They are characterized by having a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail. Chordates inhabit a wide range of habitats, from the ocean depths to the highest mountains. Lifespans vary greatly, from a few days to several decades. The current population of chordates is estimated to be around 60,000 species. They range in size from microscopic to the blue whale, the largest animal on Earth. Chordates have a variety of distinguishing features, including a backbone, four limbs, and a skull.
Name Origin: The name Chordata comes from the Latin word chorda, meaning "string" or "cord". This refers to the presence of a notochord, a flexible rod-like structure found in the embryonic stage of all chordates. The notochord is a defining feature of the phylum, and is present throughout the life of the organism.
Related Species: Amphibia, Aves, Mammalia, Reptilia