The fishlike amphioxus has a structure called a notochord which in humans develops into this column
[DOC] [TLE] Chordata facts, information, pictures | Encyclopedia.com articles ... [PAR] Chordata (krdt,d), phylum of animals having a notochord, or dorsal 
stiffening ... of bone or cartilage segments called vertebrae develops around the 
notochord; ... A lancelet has a long body, pointed at both ends, with a large 
notochord that ...