2. What is a reptile? A reptile is a vertebrate that has dry, scaly skin, lungs, and terrestrial eggs with several membranes. These allow the reptile to live it’s whole life out of water.
3. Evolution Evolved from amphibian-like ancestors After the Carboniferous Period, lakes and swamps dried up, which reduced some available habitat for water-dependent amphibians.
4. Mammal-like Reptiles Mixture of reptilian and mammalian characteristics Eventually came to dominate many land habitats During the Triassic Period (215 million years ago) Dinosaurs dominated.
5. Enter the Dinosaurs Ranged in sizes from small to enormous! Some ran on two legs or lumbered on four. All dinosaurs belonged to 1 of 2 groups Ornithischia (Bird-Hipped) Saurischia(Lizard-Hipped)
6. Exit the Dinosaurs At the end of the Crustaceous Period (65 mill. Years ago) mass extinction occurred. Multiple natural disasters Volcanic eruptions and lava flows, the dropping of sea level, and a huge asteroid or comet hitting what is now the Yucatán Peninsula in Mexico. Caused huge forest fires and dust storms ridding of the dinosaurs
7. Form and Function Well-developed lungs; a double-loop circulatory system; strong limbs; internal fertilization; and shelled, terrestrial eggs are the other adoptions that have contributed to the success of reptiles on land.
8. Body Temperature Control Reptiles control their body temperature by moving locations. To warm up, they bask in the sun during the day or stay underwater at night To stay cool, they move to the shade or go swimming, or take shelter in underground burrows. Ectotherms: An animal that relies on interactions with the environment to help it control body temp. Turtles and snakes
9. Feeding Wide range of foods Most animals eat insects. Carnivores Snakes- small animals and bird eggs Crocs/Alligators- fish and land animals Herbivores Iguanas- tears plants and swallows the chunks
10. Respiration Many reptiles have muscles around their ribs that expand the chest cavity to force air out. Snakes only have 1 lung. Spongy lungs Providing more gas exchange area than amphibians
11. Circulation The alligator and crocodile have the most developed hearts 2 atria and 2 ventricles Reptile hearts have 2 atria and 1 or 2 ventricles Double loop circulatory system One brings blood to and from the lungs Brings blood to and from the rest of the body
12. Excretion Urine produced in the kidneys Reptiles’ urine contains ammonia or uric acid Crocs and alligators consume a lot of water, which dilutes the ammonia in the urine and carries it away. Land animals convert the ammonia into uric acid. Less toxic than ammonia
13. Response A reptile’s brain is smaller than that of an amphibian. Day active animals have better vision than others. Snakes have a great sense of smell because of their lack of eyesight. Reptiles have 2 sensory organs at the top of their mouths the detect chemicals when reptiles flick their tongues.
14. Movement Reptiles with legs have stronger, larger limbs that enable them to walk, run, swim, burrow, or climb.
15. Reproduction Internal fertilization Reptiles lay eggs. Most reptiles have penis-like organs that deliver sperm to the female’s cloaca. Some snakes and lizards are ovoviviparous
16. Groups of Reptiles The four surviving groups of reptiles are snakes and lizards, crocodilians, turtles and tortoises, and the tuatara.
17. Lizards and Snakes Modern lizards and snakes belong to the order squamata, which means “scaly reptiles” Lizards Legs Clawed toes External ears Movable eyelids
18. Crocodilians Fierce carnivores that feed on other animals. Very protective over their young The females guard the eggs and carries them to a nursery area and watches over them. Only found in tropics, or subtropics where climate remains warm all year
19. Turtles and Tortoises Belong the order Testudines Have shells built in their skeletons Shell consists of 2 parts Carapace- the part of the exoskeleton that covers the cephalothorax. Plastron- Ventral part of the shell
20. Tuataras Surviving member of the order Sphenodonta Found only on a few islands off the coast of New Zealand Lack external ears and retain primitive scales
21. Ecology Endangered species Habitat being destroyed Humans hunt reptiles for food, to sell as pets, and for their skin. Sea turtle recovery programs Help babies get a head start on survival
