Reptiles

1. Reptiles

2. Reptile Examples Testudines Sphenodontia Crocodilia Squamata

3. Body Temperature Control Reptiles are ectothermic. They rely on the environment to control their temperature.

4. Covering Skin is thin and rough Watertight, allowing them to live on land Scales and Scutes (same function as scales but formed from the living dermis, rather than the epidermis) Defense Camouflage Venom Hissing Shedding tail

5. Teeth and Head Organs All of a reptile’s teeth are the same shape Replaced constantly Venom Glands Infrared Sensing Organs Parietal Eye

6. Digestive System Insectivores or carnivores Short and comparatively simple digestive tract Slower than mammals Because of the lower energy requirement of reptiles, they can digest slowly. A crocodile can live for months on a single meal

7. Respiration Lungs Diaphram

8. Heart Most 3 chambered ( 2 atria and 1 ventricle) Crocodiles have 4 chambers Systemic circulation

9. Fertilization Most sexual reproduction (some asexual) Internal fertilization Type of Birth Most are oviparous Leathery or calcareous shells Some also viviparous and oviviparous

10. Movement, Muscles, Appendages Swimming, slithering walking Skeletal muscles Paired appendages Tails Toes

11. Special Features Cold blooded Scales Toxic bacteria in mouth Velcro-like feet Regeneration Undulation Sledgehammer head Toxic Saliva

12. Big Idea 1: The process of evolution drives the diversity of life. • A. How are reptiles similar to other life? • Reptiles came from amphibians: • Increasing evolutionary pressure • Vast untouched niches of the land powered the evolutionary changes • Amphibians gradually became more and more land based. • Environmental selection propelled the development of certain traits such as scaly skin, stronger bones, ectothermic nature, and harder, more leathery eggs.

13. Big Idea 1: The process of evolution drives the diversity of life. • A. How are reptiles similar to other life? • Many birds evolved from reptiles: • transition from reptile to bird = • evolution from scales to feathers • evolution of the beak • the hollowing of bones • development of flight • warm-bloodedness • Many mammals evolved from reptiles

14. Big Idea 1: The process of evolution drives the diversity of life. • A. How are reptiles similar to other life? • Many mammals are believed to have evolved from reptiles:

15. Big Idea 1: The process of evolution drives the diversity of life. • B. How are reptiles different from other life? • Reptiles are the only animals that have: skin covered with a sheet of scales; ectothermic nature; and young that look like miniature adults (most hatched from eggs, but some born live). • The most obvious distinctions between mammals and reptiles are the fact that mammals have hair or fur, and mammary glands which they use to nourish their young.

16. Big Idea 1: The process of evolution drives the diversity of life. • B. How are reptiles different from other life? • Skeletal differences between reptiles and mammals: • Reptiles have a mouth filled with several teeth which are more or less uniform in size and shape- pointy • Mammals tend to have teeth which vary greatly in size and shape; everything from flat, multi-cusped molar teeth to the sharp cone-shaped canines

17. Big Idea 2: Biological Systems and homeostasis and reproduction • A- What adaptations allow reptiles to gather resources more efficiently: • Venom in snakes and other reptiles kills prey faster • Slow digestion/ low metabolism so that they can conserve energy and not eat as frequently • Lay out in heat, or ‘bask’ to warm blood to maintain body systems. • Snakes can spring their entire body length to strike or to catch food

18. Big Idea 2: Biological Systems and homeostasis and reproduction • A- What adaptations allow reptiles to gather resources more efficiently: • Adaptations allow reptiles to gather resources more efficiently • Dry Scaly skin: solid sheet of keratin scales. Keratin is the same substance as human hair and nails. This makes it waterproof and prevents the reptile's internal fluids from evaporating • Reptile Kidneys: very efficient, specially adapted to concentrate the body's waste products into uric acid, body absorbs most of the water, elimination requires very little fluid

19. Big Idea 2: Biological Systems and homeostasis and reproduction • B- What processes allow the organism to utilize/ conserve energy more efficiently? • Lymphatic system: Kidneys are special and secrete uric acid to conserve water • Body is ectothermic and requires that the body be developed to conserve as much energy as possible since blood is cool

20. Innate Behavior • Lizard’s tails: When a predator grabs hold of a lizard by its long tail, it can break off to allow them to escape predators. These lizards usually can grow new tails quickly. This increases the fitness of the organism by allowing it to escape and survive longer and reproduce more.

21. Learned Behavior • Playing Opossum: A species of forest chameleon will remain motionless and keel over as if dead when a predator comes very close. This tactic is intended to persuade the aggressor that the thrill of the kill has been lost, so there can be no need to press the attack. The predator may even release them. If they are released, then this tactic would add to their fitness level because they would survive longer and be able to reproduce more.

22. Cooperative Behavior • Lizards can sometimes construct an elaborate multi-tunnelled burrow for family members. This is a rare case of lizards behaving cooperatively. Multiple generations participate in construction and maintenance of burrows. DNA analysis shows that the younger individuals within the same burrow were mostly full siblings. Since a shelter was built cooperatively, the fitness of this population has been increased.

23. Big Idea 3 • As explained in the Behavior slides, living systems (such as organisms like reptiles) respond and interact with their environment through either innate behavior, learned behavior, or cooperative behavior. • How they respond to their environment usually dictates their level of fitness.

24. Big Idea 4 • Reptiles interact with their environment through different types of behavior (innate, learned, or cooperative). • Reptiles’ role in the ecosystem is to be a predator and a prey. They control the levels of insects, rodents, carrion, and fish. Reptiles are preyed on by birds and humans. They can also act as seed dispersers and pollinators. Many reptiles are keystone species, as opposed to dominant species.