Examples: Lizards, Snakes, Crocodilians, Turtles and Tortoises.

Environment  They are ectotherms- rely on behavior to help control body temperature.  Ex: lay in the sun to get warm, go under a rock or tree to cool down  Many are endangered due to habitat destruction and hunting for food, pets, or use of their skin. Food Source Some herbivores, some carnivores variety of animals and plants

Maintaining Homeostasis - Internal (Circulation, Respiration, Excretion)  Can not exchange gas through the skin, inhale and then force the air out.  Double-loop circulatory system- 1 st loop brings blood to and from the lungs, 2 nd brings blood to and from the rest of the body  Urine leaves the body in the form of waste, is held in the bladder until it is expelled Maintaining Homeostasis - External (Response)  Larger brain  Many have complex eyes and can see color well  Some snakes have a good sense of smell  Have sensory organs in the roof of their mouths that can detect chemicals when the reptile flick their tongues

Movement  Larger, stronger limbs  Legs rotated further under the body so they can carry more body weight  Turtles have flippers Reproduction  Internal fertilization  Lay eggs that develop outside the females body  Some reptiles abandon their eggs (turtles) others guard their eggs (alligators) ; others carry their eggs in their bodies and they have a live birth  Have a protective shell around the egg Evolutionary Milestone  Extotherms, 4 appendages, lay eggs on land

Picture and Vocabulary  Picture on page. 801 Figure 31-4  Vocabulary: ectotherm (800), amniotic egg(802)