Question

Why is hemichordata not a true chordata?

Answer 1

Chordata:

1. Phylum Chordata comprises all vertebrate organisms.
2. The chordates possess 5 basic characteristics during their life cycle known as a notochord, dorsal hollow nerve cord, ventral heart, pharyngeal slits, and a post-anal tail.

Hemichordates:

1. Hemichordates belong to a phylum of marine deuterostome animals.
2. Deuterostome animals have bilateral symmetry and the blastopore (the first opening in cleavage) develops into the anus during embryonic development) animals.
3. They are generally considered the sister group of the echinoderms.
4. Hemichordates do not have a notochord so they are placed under a separate phylum under non-chordates.