Notes: Reptiles and Birds Section 1: Reptiles What is a Reptile? Reptiles are terrestrial vertebrates with 3 characteristics: Dry, ____________ skin Well developed __________________ Terrestrial _______ with ________________________ Reptile Evolution Reptiles first appeared during the _________________ period, _______ mya (million years ago) Next, Earth began to cool and dry during the _________________ period. Reptiles were better equipped to survive in dry climates than ______________________ were. At the end of the Permian period, _____ mya, _____________-like reptiles became successful. At the end of the Triassic period, ____ mya, dinosaurs became the dominant animal group. Dinosaurs went extinct ____ mya at the end of the ______________________ period due to volcanic eruptions and an asteroid hitting the earth. Form and Function in Reptiles Reptiles are _____________________ – cold blooded animals that control their body temperature by moving to warm/cool areas. Respiratory system: o Reptiles have ______________ lungs that are more efficient than amphibian lungs. o Reptiles cannot ________________ through their thick, __________ skin. o Reptiles have muscles around their ________ cage to help them breathe. Circulatory system: o Reptiles have a double-loop circulatory system _______________________ loop – carries blood to/from the lungs _______________________ – carries blood to/from the rest of the body o Most reptiles have a 3 chambered heart with: 2 ___________ (left/right) 1 ventricle split by a ___________________ o __________________________ have a 4 chambered heart with 2 ventricles Excretory system o _______________ filter wastes, like ___________________, from blood to make urine. o Urine exits the body through the ____________. o Some reptiles have a urinary _____________________ to store urine. o ____________-dwelling reptiles excrete toxic ammonia into the water. o Land-dwelling reptiles turn ammonia into _______ ________, which is dried into a pasty, white solid in the cloaca to save water. Nervous system o Reptiles have large ____________________ and cerebellum in their brains. o Many reptiles have very good color vision. o Many reptiles use their tongue to catch smell molecules and carry them to a scent organ in their mouth called _______________________ organ o Reptiles transmit sounds to their inner ear through the ________________ and a bone. o Pit vipers have a _______ ______________ that detects the body heat of their prey. Reptile legs are better adapted to walking on land than amphibian legs. Reproduction o All reptiles reproduce by internal fertilization – sperm is deposited inside the female. o Most reptiles are _____________________ – some snakes and lizards are ovoviviparous. o Reptiles produce amniotic eggs with waterproof membranes and shells. ___________________– keeps water around the embryo ___________________ – allows respiration of gases inside the egg ___________________ – stores the embryo’s wastes ___________________ – contains yolk - food for the embryo o Reptiles were the first vertebrates to be able to reproduce away from ___________. Groups of Reptiles Lizards and Snakes (order _________________ – “scaly reptiles”) o Lizards and snakes have scaly skin and a double-hinged jaw. o Snakes once had legs but lost them over the course of time. Crocodilians (order __________________________) o Includes alligators, crocodiles, caimans, and gavials. o Are all carnivores that live in fresh or salt water. o Have ____ chambered hearts & take care of their young. Turtles and Tortoises (order ________________________) o Have a bony shell of 2 parts: ____________ (upper) and ____________ (lower) o Usually turtles live on water; tortoises live on land. o Do not have teeth – they have a sharp, bony beak Tuataras (order Sphenodonta) o Only 2 live on islands near New Zealand. o Tuataras look like iguanas with spiny backs. o Have very primitive ears and scales. Reptile Ecology Things that threaten reptiles: o Habitat destruction o Overhunting for food and skins o Capture of reptiles as _________. Reptiles are being protected by many programs today. Review Questions 1. Which 3 characteristics make reptiles unique? 2. Why is the evolution of the amniotic egg so important? 3. Why is uric acid so important for land-dwelling reptiles? 4. How are crocodilians different from other reptiles? Notes: Reptiles and Birds Section 2: Birds What is a Bird? Reptile-like animals that are ___________________ Have feathers made of _________ on their body, scales on their legs. o __________ feathers – insulate body for warmth o _______________ feathers – give body shape and lift for flight 2 legs and 2 front limbs that are wings. Evolution of Birds Birds share many traits with reptiles, including: o Excrete nitrogenous wastes as ________ ________. o Embryos develop inside _______________ eggs. o Similar bone structure ______________________________, a bird-like reptile from the __________________ period, looked like a dinosaur with wings and feathers. Archaeopteryx is a _____________________ species between birds and ____________________. Some scientists think that birds and dinosaurs evolved earlier from a common ancestor. Form, Function, and Flight Body Temperature Birds are endothermic – they generate their own body heat. Bird’s have a fast ___________________ to produce heat. _____________________ trap heat to keep birds warm. Feeding/Digestion Birds must eat lots of food to maintain their fast metabolism. Bird __________ are adapted to the type of food they eat. The __________: o Stores food at the end of the ___________________. o Also used to make _________ for young birds. The stomach may have a _________________ full of rocks for grinding up food. Nutrients are absorbed in the intestine and wastes released through the ____________. Respiration Birds inhale to fill _____ _______ around their lungs. Air sacs fill the lungs, where ___________ is absorbed, then exhaled. The _____-way flow of air into the lungs provides constant oxygen. Circulation Birds have an efficient ____ chambered heart: ___ atria & ____ ventricles. Oxygen-_____ and oxygen-_______ blood is not allowed to _______. 2 loops – one to the lungs (______________) and one to the body (____________) Muscular/Skeletal Birds muscles are adapted for _________________. Many bones are ____________ together to form a strong frame. Bones are ___________ and light but large to hold flight muscles. Reproduction Birds use their cloaca to perform ______________ fertilization. They lay amniotic eggs with hard ____________. Bird Ecology There are over __________ species of birds in 30 orders. Birds spread __________, pollinate flowers, and eat insects. Birds ___________ thousands of miles to escape cold winters. Review Questions 1. List 3 adaptations that birds have made for flight. 2. Why is Archaeopteryx such an important fossil? 3. How are birds different from reptiles?