Home Preparation for National Talent Search Examination (NTSE)/ Olympiad
Chapter : 4. Diversity In Living Organism
Sub-phylum : Protochordata
Sub-phylum : Protochordata The sub-phylum protochordata includes animals which are bilaterally symmetrical, unsegmented, tripolblastic and have a body cavity or coelom. The animals belonging to protochordata possess a notochord at some stage in the life history. This is flexible rod that lies between the dorsal nerve tube and the gut. The notochord provides a place for muscles to attach. It increases internal support and locomotory power. Protochordates are usually marine, soft, have worm-like or vase-like forms. Examples : Balanoglossus (a corn worm or tongue worm), Herdmania and Amphioxus, etc.