On the basis of Position of notochord, classify the different Prochordates. Justify your answer

The three sub-phylums are classified on the basis of notochord:

i. Sub phylum Hemichordata

The notochord is persistent as the stomochord in the anterior region of the animal.

ii. Sub phylum Cephalochordata

The persistent notochord extends forward beyond the brain.

iii. Sub phylum Urochordata

In Urochordata the notochord is confined to the tail region of the larva.