What is protochordates? How is it classified?

Phylum Chordata is sub-divided into the sub-phyla Protochordata and Vertebrata based on the developmental features of the notochord. Protochordata This group includes animals that have a notochord. This feature may not be present at all stages of their life cycle. Further, the notochord may not run the entire length of a protochordateâ??s body. The word â??protoâ?? means â??primitiveâ??. This indicates that protochordates are the ancestors of the modern-day chordates. General features of protochordates They are exclusively marine animals. They often live in burrows. They show an organ system level of organization and are triploblastic. The body cavity is enterocoelom. The body of a protochordate is not segmented and is bilaterally symmetrical. A notochord is present in some or all stages. Examples of protochordates: Balanoglossus,Herdmania, read less