Class Reptilia 17D

Reptile toes have claws

Reptile toes have claws

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

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

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

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

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

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