Classification of Animal Kingdom on basis of Notochord and Segmentation
Notochord: Notochord is a mesodermally derived rod-like structure on the dorsal side during the embryonic stage in some animals.
o Animals with notochord → Chordates
o Animals without notochord → Non Chordates (Porifera to echinoderms).
Segmentation: Segmentation, also called metamerism, or metameric segmentation, is the condition of being constructed of a linear series of repeating parts, each being a metamere (body segment, or somite) E.g. annelids.