Amphibia
Caecilians, Frogs and Toads, Salamanders, Amphibian Checklist and Identification Guide, Amphibian Declines in Australia, Amphibian Projects: Sri Lanka, Amphibian Research and Monitoring Initiative Atlas, Amphibian Species of the World, Amphibians of Hiroshima, Amphibians of Panama, AmphibiaWeb, Class Amphibia, Connecticut Amphibians
Aves
Anseriformes, Apodiformes, Caprimulgiformes, Charadriiformes, Ciconiiformes, Columbiformes, Coraciiformes, Cuculiformes, Falconiformes, Galliformes
Fish
Bony, Cartilaginous, Hagfish, Lampreys, Checklist of Marine Fishes of Turkey, East Coast Fish-Watch Project, Find a Fish, Fish Classification: The Classes of Fishes, Fish FAQ, Fish, A Quick Course on Ichthyology, FishBase, Gray's Reef Fish Guide, Hazardous Mediterranean Fish, Key to the Fishes of Puget Sound
Mammalia
Artiodactyla, Carnivora, Cetacea, Chiroptera, Dermoptera, Elephants, Hyracoidea, Insectivora, Lagomorpha, Macroscelidea
Reptilia
Crocodilians, Squamata, Tuataras, Turtles, Class Reptilia, Discover Canada's Aquatic Reptiles, EMBL Reptile Database, Jurassosaur's Reptipage, Reptile Image Gallery, Reptiles in Hiroshima, Reptiles of Australia, Reptiles of Panama, Reptiles of Tasmania, Sean Thomas' Snake and Herpetological Informa
Urochordata
Archives of Tunicata E-mail List, Ascidian Home Page for the United States, Just Blue, Urochordata
Chordata
Overview of the taxonomy of Phylum Chordata, which includes the well-known vertebrates (fishes, amphibians, reptiles, birds, mammals), hagfishes, tunicates, and lancelets.
Gnathostomata
Philippe Janvier's article about the jawed vertebrates in the Tree of Life website.
Phylum Chordata
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.
Subphylum Vertebrata
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.
Vertebrata
Introduction to the vertebrates and their classification, including the Hyperoartia, or lampreys, and the Gnathostomata, or jawed vertebrates.