Class Reptilia Chapter 20

Class Reptilia Reptilia - to creep Turtles, crocodiles, lizards, snakes, worm lizards, and tuatarans

Class Reptilia First vertebrates to have amniotic eggs Extraembryonic membranes Protect the embryo from desiccation Albumen Cushions Moisturizes Food source Yolk - supplies food

Class Reptilia Other adaptations for land Impervious skin Horny tales Keratin epidermal scales Horny tales Water conserving kidneys Enlarged lungs

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

Class Reptilia Characteristics of reptiles 17 orders of Reptilia 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

Class Reptilia Order Testudines Tortoise and turtles 225 Species of turtles Bony shell Limbs from internal ribs Keratinized beak

Class Reptilia Carapace - dorsal portion of shell Plastron - ventral portion of shell North American box turtle has hinges Eight cervical vertebrae

Class Reptilia Long Life span 14 or more years Up to 100 years Sexual maturity seven or eight years

Class Reptilia Oviparous Nest contain 5 - 100 eggs Development lasts 4 weeks to one year Independent young Sea turtle conservation controversy

Class Reptilia Order Rhynchocephalia Snout head Lizard-like reptiles 2 living species of Tuataras Burrow Endangered species Lizard-like reptiles Virtually unchanged from extinct members Tooth arrangement is the distinguishing factor

Class Reptilia Oviparous Share underground nesting burrows with ground-seeking sea birds Venture out of the burrow at dawn and dusk for feeding

Class Reptilia Order Squamata Three suborders Suborder Sauria - the lizards Suborder Serpentes - the snakes Suborder Amphisbaenia - worm lizards

Class Reptilia Lizards 3,300 species Two pairs of limbs Upper and lower jaws unite Vary in length Few centimeters up to 3 m

Class Reptilia Habitat Reproduction Land Dwellers Burrowers Tree Dwellers Reproduction Most are oviparous Some are viviparous or ovoviviparous

Class Reptilia Gecko Habitat Nocturnal Clicking vocalization Semitropical Climbers Adhesion disks aid Nocturnal Clicking vocalization

Class Reptilia Iguana Thick Bodies Short necks Distinct Heads Marine iguana Flying iguana Can fly 30 meters

Class Reptilia Chamelions - Group of Iguanas Characteristics Live in Africa and India Arboreal habitat Long, sticky tongue Change color Light Temperature Behavior

Class Reptilia Gila Monster and Mexican Beaded Lizard Venomous lizard Southwestern North America Not fatal to humans

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.

Class Reptilia Characteristics Lack limbs Up to 200 Vertebrae Skull Adaptations Movable upper jaw Each jaw moves independently

Class Reptilia Adaptations Differences in eye focusing Loss of left lung Displacement of Gallbladder Right Kidney Gonads

Class Reptilia Reproduction Age of snakes Oviparous Live birth Boas Garter snakes Age of snakes 135 million years old Possible relation to caecilians

Reptilia Suborder Amphisbaenia Double walk Worm Lizards 135 Species Habitat Specialized burrowers Africa, South America, Caribbean, and Mideast

Reptilia Characteristics Legless Wedge shaped head Single median tooth in upper jaw Can move forward or backward

Reptilia Order Crocodilia Greek - lizard 21 species Crocodiles, alligators, gavials, and caimans Have existed for 170 million years

Reptilia

Reptilia

Reptilia Snout is elongated Nostrils at the anterior end to help with breathing while mostly submerged Breathe and inhale water at the same time

Reptilia Tail Muscular, elongated, and laterally compressed Used for swimming, attacking prey, and maneuvers

Reptilia Teeth Stomach Laterally compressed teeth Thrashing motion of capture Swallow food whole Death roll Stomach Gizzard-like Swallow rocks and other objects

Reptilia Reproduction Oviparous Parental Care resembles that of birds Nesting and parental care can be traced to common ancestor of both groups

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

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

Reptilia Movement Prehistoric Reptiles Reptile Many were bipedal Tetrapods Primitive reptiles move like salamanders Higher than most amphibians

Reptilia Nutrition and Digestion Carnivores Tongue Turtles and crocodiles are nonprotrusible Lizards and anurans have sticky tongues May exceed the lizards length

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

Reptilia Body Regulation Gas Exchange Three chambered heart Sinous venosus is now a pacemaker

Reptilia Low oxygenated blood from right atrium to ventricle High oxygenated blood from lungs to ventricle to left atrium

Reptilia Gas exchange Across respiratory surfaces Partitioned into spongelike chambers Form a negative pressure mechanism for ventilation

Reptilia Temperature Regulation Ectotherms Can survive (-2 to 41 oC) Need (25 to 37 oC) to live Behavior is used for temperature regulation Body orientation Nocturnal Panting Blood diversion Chormatophore dispersion

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

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

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

Reptilia Osmoregulation Reabsorption of water Internal respiratory surfaces Relatively impermeable exposed skin Behavior Nocturnal Avoidance of hot surfaces Storage of water in lymphatic spaces

Reptilia Reproduction Eggs Land dwelling is possible Not completely independent of water

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

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