Question

how are the animals classified according to notochord​

Answer 1

A notochord is a primitive beginning to the backbone. It appears in embryos as a small flexible rod made from cells from the mesoderm which is one of the three layers of cells of embryos. Notochords are only found in the phylum chordata a group of animals that includes humans.

Answer 2

Notochord. The notochord is a longitudinal, cartilaginous supporting rod running beneath the nerve cord. The animal kingdom has been broadly classified into two, based on the presence or absence of notochord- Non-Chordata and Chordata. Chordates possess notochord while non-chordates lack it.