Chordates

Animals in the phylum Chordata share four key features: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

Chordata contains two subphylums of invertebrates: Urochordata (tunicates) and Cephalochordata (lancelets).

Both genomic and fossil evidence suggests that vertebrates evolved from craniates, which evolved from invertebrate chordates.

Vertebrata is a subphlyum of Chordata that is further defined by their bony backbone.