1. Class Reptilia
17D

2. Reptile toes have claws

3. Reptile toes have claws

4. Skin Special protective skin Cool, dry, leathery skin
Thick to prevent water loss
Scales composed mainly of keratin
Most reptiles must periodically molt

5. Reproduction Amniotic Egg Lays eggs encased in shells
Maintains a suitably moist environment for the developing embryo
Internal fertilization
Hard shell develops after fertilization
Porous allowing gas exchange but keeps water in

7. Most reptiles are oviparous (all turtles, crocodiles, and alligators)
Some reptiles are viviparous or ovoviviparous
Most reptiles do not care for their young

8. Respiration Possess lungs from birth
Reptile lungs include alveoli which are thin air-filled sacs
Provide more surface area for gas exchange to occur

9. Circulation Most have a 3-chambered heart similar to amphibians
Reptile ventricle is partially divided by a septum which helps keep some of the oxygenated and deoxygenated blood from mixing
Crocodiles and alligators have a 4-chambered heart

10. Nervous System 5 lobed brain Eyes
Most reptiles (excluding snakes) have a tympanum or eardrum inside an ear canal connected to an inner ear that processes sound waves
Jacobson’s organs- pits in the roof of the mouth which contain nerve endings sensitive to chemcials captured from the air by the animal’s tongue