The Phylum Chordata, the chordates, is the classication of organisms that possess a structure called a notochord, at least during some part of their development.
The best known chordates are the vertebrates (fishes, amphibians, reptiles, birds, mammals). The vertebrates and hagfishes together comprise the taxon Craniata. Also included in the phylum are the tunicates (Urochordata), lancelets (Cephalochordata). Some extinct groups are also assigned to this phylum.
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. http://animaldiversity.ummz.umich.edu/chordata.html
Overview of the taxonomy of Phylum Chordata, which includes the well-known vertebrates (fishes, amphibians, reptiles, birds, mammals), hagfishes, tunicates, and lancelets. http://tolweb.org/tree?group=Chordata&contgroup=Animals
