1. Characteristics of Reptiles

2. Characteristics of Reptiles
Class Reptilia includes snakes, lizards, crocodiles, alligators and extinct dinosaurs.
The majority of reptiles are terrestrial and are adapted to a wide range of habitats.
Alligators have a wide U-shaped, rounded snout like a shovel, crocodiles have V-shape. Teeth are wider in alligators and overlap lower jaw
Crocodile or alligator?
Gila monster
Heloderma suspectum

3. Characteristics of Reptiles
Evolved from amphibians about 350 million years ago and dominated the Earth between 245 million and 65 million years ago—the Age of Reptiles (Mesozoic era).

4. Characteristics of Reptiles
Adaptations to terrestrial life include their dry, scaly skin (resistant to water loss and wear and tear) and their amniotic egg (consists of a hard shell and multicellular membranes, which encase the embryo in a secure, self0contained aquatic environment).

5. Characteristics of Reptiles
Are ectothermic. Regulate their body temperature by controlling how much heat they absorb.
Use lungs for respiration and have a circulatory system composed of two loops and a 3-chambered heart, in which one chamber is partially divided.

7. Characteristics of Reptiles
More advanced nervous system than amphibians. Most have a highly-developed sense of smell. Are equipped with a specialized organ sensitive to low concentrations of odors called the Jacobsen’s organ, located in the roof of the mouth.

8. Characteristics of Reptiles
Excrete nitrogenous wastes in the form of uric acid. In the body, uric acid is much less toxic than ammonia or urea. Thus, it requires little water for dilution, and reptiles lose only small amounts of water in their urine.

9. Characteristics of Reptiles
More than 5,000 species of modern reptiles divided into 4 orders:
Order Testudines: turtles, tortoises, and terrapins.
Box turtle is land dweller along with larger galapagos tortoise and terrapin are semi-aqautic in nature and medium sized
Box Turtle:
Geochelone nigra vicina Galapagos tortoise
Diamondback Terrapin
Malaclemys terrapin
Terrapene ornata

10. Orders of Reptiles Order Squamata: lizards and snakes.
Anole: Anolis carolinensis
Corn snake: Elaphe guttata

11. Orders of Reptiles Order Crocodilia: crocodiles and alligators.
Siamese crocodile Crocodylus siamensis
American Alligator
Alligator mississippiensis

12. Orders of Reptiles Order Rhyncocephalia: tuataras Sphenodon punctatus
Coast of New Zealand about 40 cm or 15 inches
Sphenodon punctatus

13. Stores nitrogenous wastes produced by embryo
Surrounds all membranes and cushions developing embryo
Thin membrane enclosing the fluid in which embryo floats
Encloses the yolk
A fat-rich food supply
Provides protection from damage and evaporation of water from egg
Contains proteins and water needed by embryo

14. Characteristics of Amphibians

15. Characteristics of Amphibians
Modern amphibians share several key characteristics:
Most species change from an aquatic larval stage to a land adult form. This transformation is called metamorphosis.

16. Characteristics of Amphibians
Most have moist, thin skin with no gills.
Skin is equipped with numerous mucus glands that supply a lubricant that keeps the skin moist in air.
African Reed Frog

17. Characteristics of Amphibians
Larvae exchange oxygen and carbon dioxide through their gills and skin. Most adults lose their fills and respire through lungs and skin.

18. Characteristics of Amphibians
All adult amphibians are carnivorous, with insects and other arthropods as the most commonly consumed prey. Most amphibian larvae are herbivores, feeding on algae, bacteria, or tiny green plants.

19. Characteristics of Amphibians
Are ectothermic (external-heat).
(Amphibians are ectothermic, which means their blood temperature rises and falls with that of the surrounding environment)

20. Characteristics of Amphibians
Most have 4 pairs of limbs. Feet, if present, lack claws and are often webbed.

21. Characteristics of Amphibians
Are oviporous. Eggs lack multicellular membranes or shells. They are usually laid in water or in moist places and in most species are fertilized externally.

22. Characteristics of Amphibians
Many show parental care, guarding their eggs and keeping them moist.
Poison Arrow Frog

23. Characteristics of Amphibians
Cloaca are the primary excretory organs.
A muscular cavity at the end of the large intestine through which digestive wastes, urine and eggs or sperm leave the body.

24. Characteristics of Amphibians
A 3-chambered heart. Does not mix oxygen and deoxygenated blood very much. Little mixing increases the amount of oxygen that is delivered to the tissues.
Oxygen-poor blood goes to lungs and becomes oxygenated and travels back to the heart and out to the body.

25. Characteristics of Amphibians
The amphibian circulatory system is divided into two separate loops. One loop carries blood between the heart and lungs. The other loop carries blood to the organs and tissues in the body and returns it to the heart. This “double loop” circulation delivers blood to the body faster. Double-loop circulation occurs in amphibians and is now used by them and all other vertebrates.

26. Characteristics of Amphibians
The senses of hearing, smell, and sight are well-developed in most amphibians. Sound receptors are located in the inner ear, which is embedded within the head. Sounds are transmitted to the inner ear by the tympanic membrane, or eardrum.

27. Characteristics of Amphibians
The olfactory lobes, which are the center of the sense of smell, are larger in amphibians than in fish. The eyes can blink and are covered by a transparent, movable membrane called a nictitating membrane. Additionally, there is a continuous communication among most areas of the body.