Vertebrates – They are animals that possess a vertebral column and/or notochord at any point in their lives.
Phylum Chordata – It belongs to the Kingdom Animalia and they include both animals with a backbone and organisms without a backbone.
In some chordates the notochord only available in the larvae tail region. The notochord is present in some other chordates throughout the length of the body. In some chordates, vertebral column replaces the notochord. Because of this, not all chordates are listed in the same category.