What is the significance of Protochordates?

Answer 1

The name Protochordates literally means 'the first chordates.' The chordates include fish, amphibians, reptiles, birds and mammals. The protochordates fall into two broad groups or subphyla - the Urochordata and the Cephalochordata. Urochordata The urochordata includes the group known as the tunicates - animals whose free-swimming larvae have a notochord* and a nerve chord. The adults are sessile - that is to say they are anchored to one place on the Reef. CephalochordataCephalochordates, or lancelets, are fish-like animals that have a notochord and nerve chord along the entire length of their bodies and which persist all their lives. * A notochord is a an elongated cellular chord enclosed in a sheath, that forms the primitive skeleton of chordate embryos (including humans) and adult cephalochordates. The name Protochordates literally means 'the first chordates.' The chordates include fish, amphibians, reptiles, birds and mammals. The protochordates fall into two broad groups or subphyla - the Urochordata and the Cephalochordata. Urochordata The urochordata includes the group known as the tunicates - animals whose free-swimming larvae have a notochord* and a nerve chord. The adults are sessile - that is to say they are anchored to one place on the Reef. Cephalochordata Cephalochordates, or lancelets, are fish-like animals that have a notochord and nerve chord along the entire length of their bodies and which persist all their lives. * A notochord is a an elongated cellular chord enclosed in a sheath, that forms the primitive skeleton of chordate embryos (including humans) and adult cephalochordates.