Do larval and adult lampreys have the 5 chordate characteristics? Which feature has evolved into a new structure? What characteristics make them craniates? Do they have the vertebrate characteristics? Solution The larvae of lamprey is called ammocoetes.larvae of lamprey have the 5 chordate characteristics such as notochord,dorsal nerve cord,pharyngeal slits,endostyle and post anal tail.endostyle is present in larvae stage but not in adult lamprey. A well developed cranium and jaw bone makes them craniates..