Bellow there are notes that will help you to get acquainted with chordates.
Chordates are defined as organisms that possess a structure called a notochord, at least during some part of their development.
http://bioserv.fiu.edu/~biolab/labs/1011/supplemental_materials/
http://animaldiversity.ummz.umich.edu/accounts/Chordata/
http://biology.clc.uc.edu/courses/bio106/chordate.htm
