Chordate

A chordate is an animal that has 5 synapomorphies (notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits) or primary characteristics at some point, whether at larval or adult stages to distinguish them from all other species. Chordates are divided into three subphylum, which includes Vertebrata (which includes mammals, birds, reptiles, amphibians, and fish), Tunicata (sea squirts and salps), and Cephalochordata (lancelets). Of the more than 65,000 species of chordates, half of them are bony fish, part of the superclass, Osteichthyes.