• Have a backbone
  • Have dry, scaly skin that sheds periodically during growth
  • Most live on land
  • Eggs typically laid on land and have a leathery, flexible shell; in some, female retains egg inside body but developing embryo is nourished by a yolk rather than by mother's body
  • Embryo is surrounded by watery fluid, called amnion; this egg is called an amniotic egg; animals that lay eggs in water, such as fish and amphibians, do not make amniotic eggs
  • Are cold blooded, or more appropriately, ectothermic; they must absorb heat from their environment rather than generating it inside their body
  • Breathe with lungs
  • Kingdom: Animalia
    • Phylum: Chordata
      • Class: Reptilia
        • Order: Crocodilia (crocodiles, alligators), Rhynchocephalia (tuataras), Squamata (lizards, snakes), Testudines (turtles)