'Tetrapod' groups 'with four limbs'; these may also be categorized as Amniota (mammals, reptiles, dinosaurs and birds), with all living and fossil amphibians placed in various non-amniote groups -- [ ucmp ]; Amphibia and Reptilia together are sometimes referred to as 'herptiles' --[ general herpetology links ] Amphibia amphibians spend part of their life in water, breathe through skin & gills, lay eggs in water and lack scales, cold blooded -- [ ucmp | links | Amphibian Species of the World ] Labyrinthodontia fossils Lepospondyli fossils Lissamphibia includes all living amphibians -- [ ToL | ummzADW ] Anura (=Salienta) frogs, toads -- [ ToL | ummzADW | links ] Bufonidae toads [ ummzADW ] Centrolenidae Centrolenella [ ummzADW ] Dendrobatidae poison dart frogs [ ummzADW ] Discoglossidae Alytes [ ummzADW ] Hylidae tree frogs and peepers [ ummzADW ] Hyperolidae Hyperolius [ ummzADW ] Leptodactylidae Syrrhophus, Telmatobius [ ummzADW ] Microhylidae narrowmouth toad [ ummzADW ] Myobatrachidae gastric brooding frog [ ummzADW ] Pelobatidae spadefoot toads [ ummzADW ] Pipidae Surinam toad, Afr. clawed frog [ ummzADW ] Pseudidae Pseudis [ ummzADW ] Ranidae true frogs [ ummzADW ] Rhacophoridae flying frogs [ ummzADW ] Rhinophrynidae burrowing toad [ ummzADW ] Caudata (=Urodela) salamanders, newts, mudpuppy -- [ ToL | ummzADW | links ] Amphiumidae amphiumas [ ToL | ummzADW ] Plethodontidae lungless salamanders [ ToL | ummzADW ] Salamandridae newts and true salamanders [ ToL | ummzADW ] Dicamptodontidae Pacific giant salamanders [ ToL ] Ambystomatidae mole salamanders [ ToL | ummzADW ] Proteidae Necturus (mudpuppy, waterdogs) and Proteus [ ToL | ummzADW ] Rhyacotritonidae torrent salamanders [ ToL ] Cryptobranchidae hellbenders [ ToL | ummzADW ] Hynobiidae hynopids (Asian) salamanders [ ToL | ummzADW ] Sirenidae sirens [ ToL | ummzADW ] Gymnophiona (=Apoda) caecilians -- [ ummzADW | links | amnh | hofer ] Caecilidaeidae -- [ ummzADW ] Ichthyophiidae -- [ ummzADW ] Typhlomectidae -- [ ummzADW ] Reptilia reptiles have scales and an amniote egg adapted to survival out of water, cold blooded and mostly well adapted to life on land; contains many fossil groups including the dinosaurs -- [ ummzADW | links | EMBL Reptile Db | WWWVL ]; modern taxonomy often places the lizards, crocodiles, birds, Sphenodon, and their extinct relatives into one amniote group -- the Diapsida -- [ ToL : ucmp ]. Anapsida -- [ ucmp ] Testudines tortoises, turtles -- [ ummzADW | links | ucmp ] Cryptodira Chelonia -- [ ucmp ] Chelydridae snapping turtles [ embl | ummzADW ] Emydidae pond, box and water turtles [ embl | ummzADW ] Testudinidae tortoises [ embl | ummzADW ] Dermatemydidae river turtles [ embl ] Kinosternidae Mud and Musk Turtles [ embl | ummzADW ] Carettochelyidae Pignose Turtles [ embl ] Trionychidae Softshell Turtles [ embl | ummzADW ] Cheloniidae Sea Turtles [ embl | ummzADW ] Dermochelyidae Leatherback Turtles [ embl | ummzADW ] Pleurodira Pelomedusidae Afro-American Sideneck Turtles [ embl ] Chelidae Austro-American Sideneck Turtles [ embl ] Lepidosauria Rhynchocephalia [ ummzADW ] Sphenodontidae Tuataras [ embl | ummzADW ] Squamata -- [ ummzADW ] Sauria Lacertilia -- Lizards -- [ links ] Iguania Agamidae Agamas, Bearded Dragon, Pogona [ embl | ummzADW ] Chamaeleonidae Chameleons [ embl | ummzADW ] Iguanidae Iguanas and Spinytail Iguanas [ embl | ummzADW ] Corytophaninae Casquehead Lizards [ embl ] Crotaphytinae Collared and Leopard Lizards [ embl ] Hoplocercinae Hoplocercinae [ embl ] Iguaninae Iguanas and Spinytail Iguanas [ embl ] Oplurinae Madagascar iguanids [ embl ] Phrynosomatinae Earless, Spiny, Tree, Side-blotched and Horned Lizards [ embl ] Polychrotinae Anoles [ embl ] Tropidurinae Neotropical Ground Lizards [ embl ] Gekkota Gekkonidae Geckoes [ embl | ummzADW ] Pygopodidae Legless Lizards [ embl ] Dibamidae Blind Lizards [ embl ] Scincomorpha Cordylidae Spinytail Lizards [ embl ] Gerrhosauridae Plated Lizards [ embl ] Gymnophthalmidae Spectacled Lizards [ embl ] Teiidae Whiptails and Tegus [ embl | uumzADW ] Lacertidae Lacertids, Wall Lizards [ embl | ummzADW ] Scincidae Skinks [ embl ] Xantusiidae Night Lizards [ embl ] Diploglossa Anguidae Glass Lizards and Alligator Lizards; Lateral Fold Lizards [ embl | ummzADW] Anniellidae American Legless lizards [ embl ] Xenosauridae Knob-scaled Lizards [ embl ] Platynota Varanoidea Helodermatidae Gila Monsters [ embl ] Lanthanotidae Earless Monitor lizards [ embl ] Varanidae Monitor Lizards [ embl | uumzADW ] Amphisbaenia Worm Lizards -- [ links | ummzADW | hofer ] Amphisbaenidae Worm Lizards [ embl ] Trogonophidae Shorthead Worm Lizards [ embl ] Bipedidae Two-legged Worm Lizards [ embl ] Ophidia Serpentes -- snakes -- [ links ] Anomalepidae Dawn Blind Snakes [ embl ] Typhlopidae Blind Snakes [ embl ] Leptotyphlopidae Glauconiidae -- Slender Blind Snakes [ embl ] Aniliidae Pipe Snakes [ embl ] Anomochilidae Dwarf Pipe Snakes [ embl ] Boidae Boas and Pythons [ embl : ummzADW ] Bolyeridae Round Island Boas [ embl ] Cylindrophiidae Asian Pipe Snakes [ embl ] Loxocemidae Mexican Burrowing Pythons [ embl ] Tropidophiidae Woodsnakes, Round Island "Boas " [ embl ] Uropeltidae Shield-tail Snakes [ embl ] Xenopeltidae Sunbeam Snakes [ embl ] Acrochordidae File Snakes [ embl : uumzADW ] Uropeltidae Mole Vipers [ embl ] Colubridae Colubrids [ embl : ummzADW ] Elapidae Cobras, Kraits, Coral Snakes [ embl : ummzADW ] Hydrophiidae Sea Snakes [ embl ] Viperidae Rattlesnakes, Vipers and Pit Vipers [ embl : ummzADW ] Archosauria Crocodylia Alligators, Crocodiles, Gavials -- [ embl | Photo Gallery | uumzADW | links ] Alligatoridae Alligators, Caiman -- [ ummzADW | embl | Britton ] Crocodylidae Crocodiles, False Gavial, Tomistoma -- [ ummzADW | embl | Britton] Gavialidae Gavials -- [ ummzADW | embl | Britton ]