Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 31 Reptiles and Birds 31.1: Reptiles pgs. 796-805 Characteristics of Reptiles Class Reptilia First animals to adapt to land Have dry scaly skin w/ claws Have lungs Legs at right angles from body Means – to creep Provides greater support and make walking and running on land easier Most have 3 chambered heart; some have 4 chambered heart (crocodilians) Characteristics of Reptiles Ectotherms (cold blooded) Most are herbivores but some are carnivores Internal fertilization (sexually) Lay eggs on land (amniotic eggs) Provides nourishment and protection to developing embryo Use sense organs to detect prey or ID chemicals What is a Reptile? Ectotherms (cold Blooded) with dry, scaly skin, with claws on their toes More advanced 3 chambered hearts (crocs have 4) What is a Reptile? Amniotic eggs Allows reptiles to be successful on land Evolution Reptiles Reptiles were the first animals to adapt their eggs to dry habitats First reptiles are from 350 mya Did not become common until about 40-50 million years later when the conditions of Earth were drier Mammal-Like Reptiles At the end of the Permian Period ~245 mya, a great variety of reptiles roamed the Earth Mammal-Like Reptiles Displayed a mixture of mammalian and reptilian characteristics Dominated many land habitats Became extinct in just a few million years Replaced by another group of reptiles… Enter the Dinosaurs Late Triassic and Jurassic periods Two groups of large aquatic reptiles swam in the seas Ancestors of modern turtles, crocodiles, lizards, and snakes populated many land habitats Enter the Dinosaurs Dinosaurs were everywhere! Saurischia: lizard-hipped dinosaurs Ornithischia: bird-hipped dinosaurs Dinosaurs are the ancestors of modern birds Exit the Dinosaurs Mass Extinction 65 mya: the end of the Cretaceous Period Caused by a dramatic series of natural disasters Volcanic eruptions, dropping in sea level, huge asteroid or comet smashing into the now Yucatan Peninsula in Mexico, etc. Opened up niches on land and in the sea, providing opportunities for other kinds of organisms to evolve Body Temperature Control Reptiles are ectotherms They rely on behavior to help control body temperature To warm up, they bask in the sun To cool down, they move to the shade Reptile Feeding & Respiration Reptiles range from herbivores to carnivores The lungs of reptiles are spongy, providing more gas exchange area than those of amphibians Most reptiles have 2 efficient lungs to exchange gas with the environment Reptile Circulation Reptiles have an efficient double-loop circulatory system Their heart contains two atria and either one or two ventricles Reptile Circulation Reptile Excretion Urine is produced in the kidneys of reptiles By eliminating wastes that contain little water, a reptile can conserve water Reptile Response The basic pattern of a reptile’s brain is similar to that of an amphibian In addition to a pair of nostrils, most reptiles have a pair of sensory organs in the roof of the mouth that can detect chemicals Reptiles have simple ears and can pick up on ground vibrations and body heat Reptile Reproduction All reptiles reproduce by internal fertilization Most reptiles are oviparous (lay eggs that develop outside the mother’s body) Reptilian eggs are amniotic They contain a shell and membranes that create a protected environment in which the embryo can develop without drying out Structure of an Amniotic Egg Groups of Reptiles 4 orders Squamata (snakes and lizards) Lizards live on the ground, burrows, trees or water Snakes - have no limbs; kill prey by constriction or venom and swallowing whole Chelonia (turtles) Protected by a 2-part shell (dorsal-carapace & ventral-plastron) Some are aquatic, others are terrestrial No teeth but powerful jaws w/ beak-like structure Most are herbivores Groups of Reptiles 4 orders (continued) Crocodilia (crocodiles and alligators) Crocodiles have long slender snouts Alligators have short broad shouts Fresh and salt water 4 chambered heart Rhynchocephalia (tuatara) Only survivor of primitive group of reptiles Diversity of Reptiles Lizards Includes the largest lizard, the Komodo Dragon Snakes Includes rattlesnakes, copperheads, water moccasins, & coral snakes Diversity of Reptiles Carapace(Dorsal) Turtles and tortoises Plastron(Ventral) The only with hinged shells Crocodilians The only Reptiles with 4 chambered hearts Diversity of Reptiles Snakes feed in a variety of ways: Constrictors kill prey by suffocation Venomous snakes kill prey by poisoning Most snakes simply grab prey and swallow it whole Diversity of Reptiles Reptiles have special sense organs: “Pit” of rattlesnakes allows them to detect heat of warm-blooded prey Jacobson’s organ in roof of snakes mouth allows them to detect odors brought in by forked tongue Ecology of Reptiles Many are in danger because of loss of habitat Humans also hunt them for food, to sell as pets, for their skins, etc. Some are now protected 31.2: Birds Pgs. 806-814 Pictures of Birds Characteristics of Birds Class Aves Feathers, wings and thin hollow bones which allow for flight Keel shaped sternum 4 chambered heart Respiratory systems consist of: lungs, anterior and posterior air sacs Endotherms (warm blooded) Able to regulate their internal body temperature Characteristics of Birds Internal fertilization (sexual) Amniotic eggs w/ hard shell Incubate their eggs (keep at a consistent temperature) Adaptations of birds Feathered legs and feet of ptarmigans Modified wings and feet of penguins Large eyes, acute sense of hearing and sharp claws of owls Long beaks of hummingbirds What is a Bird? Class Aves Feathers, modified scales that provide insulation & flight Wings, power provided by muscles attached to sternum (breastbone) What is a Bird? Other adaptations for flight include hollow bones, high metabolism maintained by 4 chambered heart & air sacs Endotherm, maintains a nearly constant body temperature that does not depend on environment Form, Function, and Flight Body Temperature Control Birds are endotherms (animals that can generate their own body heat) They have a high rate of metabolism compared to ectotherms (metabolism produces heat) A bird’s feathers insulate its body enough to conserve most of its metabolic energy Bird Feeding The more food a bird eats, the more heat energy its metabolism can generate For this reason, the phrase “eats like a bird” is quite misleading – birds are voracious eaters A bird’s beak, or bill, is adapted to the type of food they eat Bird Digestion Bird Respiration When a bird inhales, most air first enters large posterior air sacs in the body cavity and bones The inhaled air then flows through the lungs in a series of small tubes A complex system of air sacs and breathing tubes ensures that air flows into the air sacs and out through the lungs in a single direction This constant, one way flow of oxygen-rich air helps birds maintain their high metabolic rate and generates enough energy for flight Bird Circulation Circulation 4 chambered hearts and two separate circulatory loops Structure of Bird’s Heart Domestic pigeon Right atrium Heart Right ventricle Left atrium Left ventricle Complete division Bird Excretion Excretion Similar to those of reptiles – white, pasty uric acid droppings Bird Response Response Well developed sense organs Well developed eyes that can see color Excellent hearing Reproduction in Birds Bird eggs are amniotic eggs They have hard outer shells Most birds incubate their eggs until they hatch Diversity of Birds A bird’s lifestyle is determined by its type of beak and feet. Diversity of Birds Diversity of Birds