Characteristic features of Vertebrates are: 1. These animals have a true vertebral column and internal skeleton, allowing a completely different distribution of muscle attachment points to be used for movement. 2. The members of subphylum Vertebrata possess notochord during the embryonic period. 3. The notochord is replaced by a cartilaginous or bony vertebral column in the adult. 4. Thus all vertebrates are chordates but all chordates are not vertebrates. 5. Besides the basic chordate characters, vertebrates have a ventral muscular heart with two, three or four chambers, kidneys for excretion and osmoregulation and paired appendages which may be fins or limbs. 6. Vertebrates are bilaterally symmetrical, triploblastic, coelomic and segmented, with complex differentiation of body tissues and organs.