Brief introduction to the chordates, defined as organisms that possess a structure called a notochord, at least during some part of their development. Includes links to information about subgroups and representative animals.
Philippe Janvier's article about the jawed vertebrates in the Tree of Life website.
What makes a vertebrate a vertebrate? They have more in common than a backbone. Find out more in this site from the Animal Diversity Web.
Introduction to the vertebrates and their classification, including the Hyperoartia, or lampreys, and the Gnathostomata, or jawed vertebrates.
Overview of the taxonomy of Phylum Chordata, which includes the well-known vertebrates (fishes, amphibians, reptiles, birds, mammals), hagfishes, tunicates, and lancelets.