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Class Reptilia Chapter 20 Slide 2 Class Reptilia Reptilia - to creep Turtles, crocodiles, lizards, snakes, worm lizards, and tuatarans Slide 3 Class Reptilia First vertebrates to have amniotic eggs Extraembryonic membranes Protect the embryo from desiccation Albumen Cushions Moisturizes Food source Yolk - supplies food Slide 4 Class Reptilia Other adaptations for land Impervious skin Keratin epidermal scales Horny tales Water conserving kidneys Enlarged lungs Slide 5 Class Reptilia Subclass Anapsida lack openings in the temple Turtles Subclass Diapsida Lower and upper openings in the temporal region of the skull Snakes, lizards, and tuataras Subclass Synapsida single dorsal opening in the temporal region of the skull Slide 6 Class Reptilia Characteristics of reptiles Skull with one surface Respiration by lungs Metanephric kidneys Internal fertilization Amniotic eggs Very dry skin with keratinized scales 17 orders of Reptilia 4 Living orders of Reptilia Slide 7 Class Reptilia Order Testudines Tortoise and turtles 225 Species of turtles Bony shell Limbs from internal ribs Keratinized beak Slide 8 Class Reptilia Carapace - dorsal portion of shell Plastron - ventral portion of shell North American box turtle has hinges Eight cervical vertebrae Slide 9 Class Reptilia Long Life span 14 or more years Up to 100 years Sexual maturity seven or eight years Slide 10 Class Reptilia Oviparous Nest contain 5 - 100 eggs Development lasts 4 weeks to one year Independent young Sea turtle conservation controversy Slide 11 Class Reptilia Order Rhynchocephalia Snout head 2 living species of Tuataras Burrow Endangered species Lizard-like reptiles Virtually unchanged from extinct members Tooth arrangement is the distinguishing factor Slide 12 Class Reptilia Oviparous Share underground nesting burrows with ground- seeking sea birds Venture out of the burrow at dawn and dusk for feeding Slide 13 Class Reptilia Order Squamata Three suborders Suborder Sauria - the lizards Suborder Serpentes - the snakes Suborder Amphisbaenia - worm lizards Slide 14 Class Reptilia Lizards 3,300 species Two pairs of limbs Upper and lower jaws unite Vary in length Few centimeters up to 3 m Slide 15 Class Reptilia Habitat Land Dwellers Burrowers Tree Dwellers Reproduction Most are oviparous Some are viviparous or ovoviviparous Slide 16 Class Reptilia Gecko Habitat Semitropical Climbers Adhesion disks aid Nocturnal Clicking vocalization Slide 17 Class Reptilia Iguana Thick Bodies Short necks Distinct Heads Marine iguana Flying iguana Can fly 30 meters Slide 18 Class Reptilia Chamelions - Group of Iguanas Characteristics Live in Africa and India Arboreal habitat Long, sticky tongue Change color Light Temperature Behavior Slide 19 Class Reptilia Gila Monster and Mexican Beaded Lizard Venomous lizard Southwestern North America Not fatal to humans Slide 20 Class Reptilia Suborder - Serpentes Snakes 2,300 Species 300 are venomous 30,000 - 40,000 humans die each year Most occur in Southeast Asia < 100 Occur in the U.S. Slide 21 Class Reptilia Characteristics Lack limbs Up to 200 Vertebrae Skull Adaptations Movable upper jaw Each jaw moves independently Slide 22 Slide 23 Slide 24 Class Reptilia Adaptations Differences in eye focusing Loss of left lung Displacement of Gallbladder Right Kidney Gonads Slide 25 Class Reptilia Reproduction Oviparous Live birth Boas Garter snakes Age of snakes 135 million years old Possible relation to caecilians Slide 26 Reptilia Suborder Amphisbaenia Double walk Worm Lizards 135 Species Habitat Specialized burrowers Africa, South America, Caribbean, and Mideast Slide 27 Reptilia Characteristics Legless Wedge shaped head Single median tooth in upper jaw Can move forward or backward Slide 28 Reptilia Order Crocodilia Greek - lizard 21 species Crocodiles, alligators, gavials, and caimans Have existed for 170 million years Slide 29 Reptilia Slide 30 Reptilia Slide 31 Reptilia Snout is elongated Nostrils at the anterior end to help with breathing while mostly submerged Breathe and inhale water at the same time Slide 32 Reptilia Tail Muscular, elongated, and laterally compressed Used for swimming, attacking prey, and maneuvers Slide 33 Reptilia Teeth Laterally compressed teeth Thrashing motion of capture Swallow food whole Death roll Stomach Gizzard-like Swallow rocks and other objects Slide 34 Reptilia Reproduction Oviparous Parental Care resembles that of birds Nesting and parental care can be traced to common ancestor of both groups Slide 35 Reptilia External Structures Skin No respiratory function Thick, dry, and keratinized scales Shedding of the scales is called ecdysis Pheromones are secreted Cryptic, Aposematic, and mimicry coloration Slide 36 Reptilia Support Skeleton resembles amphibian form Skull is elongated Secondary palate Increase in cervical vertebrae Atlas and axis increase head movement Ribs can be highly modified Cobra Flying lizards Autotomy - loss of a tail Slide 37 Reptilia Movement Prehistoric Reptiles Many were bipedal Reptile Tetrapods Primitive reptiles move like salamanders Higher than most amphibians Slide 38 Reptilia Nutrition and Digestion Carnivores Tongue Turtles and crocodiles are nonprotrusible Lizards and anurans have sticky tongues May exceed the lizards length Slide 39 Reptilia Snakes Glottis is far forward to allow for breathing Vipers have hollow fangs that are hinged on the maxillary Coral, sea, and cobra snakes rigid fangs Some cobras can spit Venom glands are modified salivary glands Slide 40 Reptilia Body Regulation Gas Exchange Three chambered heart Sinous venosus is now a pacemaker Slide 41 Reptilia Low oxygenated blood from right atrium to ventricle High oxygenated blood from lungs to ventricle to left atrium Slide 42 Reptilia Gas exchange Across respiratory surfaces Across respiratory surfaces Partitioned into spongelike chambers Partitioned into spongelike chambers Form a negative pressure mechanism for ventilation Form a negative pressure mechanism for ventilation Slide 43 Reptilia Temperature Regulation Ectotherms Can survive (-2 to 41 o C) Need (25 to 37 o C) to live Behavior is used for temperature regulation Body orientation Nocturnal Panting Blood diversion Chormatophore dispersion Slide 44 Reptilia Nervous and Sensory Functions Cerebral hemisphere is larger than in Amphibians Improved smell Jacobson organ Snakes can smell with their tongue Improved vision motor coordination Ears detect vibrations Snakes have heat sensitive pit organs Slide 45 Reptilia Optic lobe and Cerebellum are enlarged Increased vision More refined motor coordination Independent eye movement Different fields of vision Dominant sense in most reptiles Colored vision Slide 46 Reptilia Excretion Kidneys have more nephrons or blood filtering units (Metanephric kidneys) More blood flow Higher pressure Excrete uric acid Insoluble in water Can be stored as a paste Slide 47 Reptilia Osmoregulation Reabsorption of water Internal respiratory surfaces Relatively impermeable exposed skin Behavior Nocturnal Avoidance of hot surfaces Storage of water in lymphatic spaces Slide 48 Reptilia Reproduction Eggs Land dwelling is possible Not completely independent of water Slide 49 Reptilia Internal Fertilization Egg shell forms after Males have an intromittent organ Sperm can be stored by the female Turtles 4 years Snakes 6 years Slide 50 Reptilia Parthenogenesis 6 families of lizards 1 family of snake Parental Care Eggs are usually abandoned 100 species of reptiles take care of their young American alligator Sex is temperature dependent