2 All are vertebrates and belong to the Phylum Chordata “chordates” To be a chordate, certain characteristics must be present at sometime during its life.Notochord (p.395)- a rod-like piece of cartilage that runs along the dorsal side.
3 - it is present in humans during early development. - it turns into the backbone.
4 some have a notochord their entire life. (not vertebrates). Example 1: tunicate