
Reptiles are animals in the (Linnaean) class Reptilia. They are characterized by breathing air, laying shelled eggs, and having skin covered in scales and/or scutes. Reptiles are classically viewed as having a "cold-blooded" metabolism. They are tetrapods (either having four limbs or being descended from four-limbed ancestors). Modern reptiles inhabit every continent with the exception of Antarctica, and four living orders are currently recognized: Crocodilia (crocodiles, gavials, caimans, and alligators) Sphenodontia (tuataras from New Zealand) Squamata (lizards, snakes, and worm lizards) Testudines (turtles and tortoises) Amphibians (class Amphibia, from Amphi- meaning "on both sides" and -bios meaning "life"), such as frogs, salamanders, and caecilians, are ectothermic (or cold-blooded) animals that metamorphose from a juvenile water-breathing form, either to an adult air-breathing form, or to a paedomorph that retains some juvenile characteristics. Mudpuppies, for example, retain juvenile gills in adulthood. The three modern orders of amphibians: Anura (frogs and toads), Caudata (salamanders and newts) Gymnophiona (caecilians, limbless amphibians that resemble snakes)
Reptiles
Amphibians
David
Attenborough
turtles
tortoises
lizards
snakes
worm
tuataras
crocodiles
gavials
caimans
alligators
frogs
toads
salamanders
newts
caecilians