Characteristics of ReptilesCharacteristics of Reptiles

By Jerit OwensBy Jerit Owens

Scaly SkinScaly Skin

Dry thick skin covered with scalesDry thick skin covered with scalesPrevents water lossPrevents water lossAdds protection against predatorsAdds protection against predatorsSkin does NOT play a role in respiration in Skin does NOT play a role in respiration in

reptiles. They can only respire through reptiles. They can only respire through their lungs.their lungs.

Skeletal Features Compared to Skeletal Features Compared to AmphibiansAmphibians

Legs are placed directly under body than Legs are placed directly under body than at right angles, unlike amphibians.at right angles, unlike amphibians.

This provides greater support for walking This provides greater support for walking and running.and running.

Reptiles have claws for catching prey and Reptiles have claws for catching prey and for protection.for protection.

More evolved jaws and teeth.More evolved jaws and teeth.

Some have Four-chambered Some have Four-chambered HeartsHearts

Most have three chambered heartsMost have three chambered heartsCrocodilians have four chambered heartsCrocodilians have four chambered heartsThis separates deoxygenated blood from This separates deoxygenated blood from

oxygenated blood.oxygenated blood.Enables more oxygen to reach tissues.Enables more oxygen to reach tissues.Supports high level of energy use.Supports high level of energy use.

Reproduce on LandReproduce on Land

Lay eggs on landLay eggs on land No water larval stage, so they No water larval stage, so they

are not at risk to water are not at risk to water predators like amphibianspredators like amphibians

No type of metamorphosis, No type of metamorphosis, hatchlings look just like adultshatchlings look just like adults

Evolution of the amniotic egg Evolution of the amniotic egg freed reptiles from freed reptiles from reproduction in water.reproduction in water.

Amniotic egg nourishes and Amniotic egg nourishes and protects the developing protects the developing embryo in terrestrial habitats.embryo in terrestrial habitats.

Reproduce on Land (cont’d)Reproduce on Land (cont’d)

Embryo relies on egg for Embryo relies on egg for survival until it hatches.survival until it hatches.

All have internal All have internal fertilizationfertilization

Eggs are laid after Eggs are laid after fertilizationfertilization

Reptiles lay eggs in safe Reptiles lay eggs in safe places, away from places, away from predatorspredators

Most reptiles provide no Most reptiles provide no care for hatchlings.care for hatchlings.

Reptiles are EctothermsReptiles are Ectotherms Similar to amphibians Similar to amphibians

because they are both because they are both ectotherms.ectotherms.

Rely on outer Rely on outer environment for environment for regulation of body regulation of body temperature.temperature.

Because of this feature, Because of this feature, they don’t live in they don’t live in extremely cold regions.extremely cold regions.

Many become dormant in Many become dormant in cold seasons.cold seasons.

This lizard is sun bathing to get warm.

Obtaining FoodObtaining Food Slow animals like turtles Slow animals like turtles

and tortoises are and tortoises are herbivores or they prey herbivores or they prey on worms and mollusks. on worms and mollusks.

Fast turtles can prey on Fast turtles can prey on fish and amphibiansfish and amphibians

Most lizards eat insectsMost lizards eat insects Marine iguanas from the Marine iguanas from the

Galapagos Islands eat Galapagos Islands eat algae.algae.

Komodo dragons are Komodo dragons are carnivorous and feed on carnivorous and feed on large animals including large animals including humans.humans.

This marine iguana is brightly colored from eating algae in the Galapagos Islands.

Obtaining Food (cont’d)Obtaining Food (cont’d)

Some snakes like Some snakes like rattle snakes have rattle snakes have fangs for capturing fangs for capturing prey.prey.

Other large snakes Other large snakes use methods of use methods of constriction to constriction to suffocate their prey.suffocate their prey.

Sense OrgansSense Organs Some snakes have heat-Some snakes have heat-

detecting pits below their eyes, detecting pits below their eyes, to detect warm prey.to detect warm prey.

Snakes and lizards flick their Snakes and lizards flick their tongue to sense chemical tongue to sense chemical molecules in the air.molecules in the air.

They then pull the tongue into They then pull the tongue into the mouth and insert it into a the mouth and insert it into a structure call the Jacobson’s structure call the Jacobson’s organ.organ.

This organ performs a This organ performs a chemical analysis of the chemical analysis of the molecules that are on the molecules that are on the tonguetongue

This image shows the Jacobson’s organ.