Chordata
The phylum chordata consists of mostly vertebrate animals. Some of the main classes of chordates include mammals, fish, birds, reptiles and amphibians. Humans belong to this phylum. At some stage of their lives every chordate will have a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, and a post anal tail. There are more than 65,000 known species of chordates. Vertebrate chordates are bilaterally symmetrical and are segmented.