Class ReptiliaChapter 20

Class Reptilia Reptilia - to creepTurtles, crocodiles, lizards, snakes, worm lizards, and tuatarans

Class ReptiliaFirst vertebrates to have amniotic eggsExtraembryonic membranesProtect the embryo from desiccationAlbumenCushionsMoisturizes Food sourceYolk - supplies food

Class ReptiliaOther adaptations for landImpervious skinKeratin epidermal scalesHorny talesWater conserving kidneysEnlarged lungs

Class ReptiliaSubclass Anapsida lack openings in the templeTurtlesSubclass DiapsidaLower and upper openings in the temporal region of the skullSnakes, lizards, and tuatarasSubclass Synapsida single dorsal opening in the temporal region of the skull

Class Reptilia Characteristics of reptilesSkull with one surfaceRespiration by lungsMetanephric kidneysInternal fertilizationAmniotic eggsVery dry skin with keratinized scales17 orders of Reptilia 4 Living orders of Reptilia

Class ReptiliaOrder TestudinesTortoise and turtles225 Species of turtlesBony shellLimbs from internal ribsKeratinized beak

Class ReptiliaCarapace - dorsal portion of shellPlastron - ventral portion of shellNorth American box turtle has hingesEight cervical vertebrae

Class ReptiliaLong Life span14 or more yearsUp to 100 yearsSexual maturity seven or eight years

Class ReptiliaOviparousNest contain 5 - 100 eggsDevelopment lasts 4 weeks to one yearIndependent youngSea turtle conservation controversy

Class ReptiliaOrder RhynchocephaliaSnout head2 living species of TuatarasBurrowEndangered speciesLizard-like reptilesVirtually unchanged from extinct membersTooth arrangement is the distinguishing factor

Class ReptiliaOviparousShare underground nesting burrows with ground-seeking sea birdsVenture out of the burrow at dawn and dusk for feeding

Class ReptiliaOrder SquamataThree subordersSuborder Sauria - the lizardsSuborder Serpentes - the snakesSuborder Amphisbaenia - worm lizards

Class ReptiliaLizards 3,300 speciesTwo pairs of limbs Upper and lower jaws uniteVary in length Few centimeters up to 3 m

Class ReptiliaHabitatLand Dwellers BurrowersTree DwellersReproductionMost are oviparousSome are viviparous or ovoviviparous

Class ReptiliaGeckoHabitatSemitropicalClimbersAdhesion disks aidNocturnalClicking vocalization

Class ReptiliaIguanaThick BodiesShort necksDistinct HeadsMarine iguanaFlying iguanaCan fly 30 meters

Class ReptiliaChamelions - Group of IguanasCharacteristicsLive in Africa and IndiaArboreal habitatLong, sticky tongue Change colorLightTemperatureBehavior

Class ReptiliaGila Monster and Mexican Beaded LizardVenomous lizardSouthwestern North AmericaNot fatal to humans

Class ReptiliaSuborder - SerpentesSnakes2,300 Species300 are venomous30,000 - 40,000 humans die each yearMost occur in Southeast Asia< 100 Occur in the U.S.

Class ReptiliaCharacteristicsLack limbsUp to 200 VertebraeSkull AdaptationsMovable upper jaw Each jaw moves independently

Class ReptiliaAdaptationsDifferences in eye focusingLoss of left lungDisplacement of GallbladderRight KidneyGonads

Class ReptiliaReproduction OviparousLive birth BoasGarter snakesAge of snakes135 million years oldPossible relation to caecilians

ReptiliaSuborder AmphisbaeniaDouble walk Worm Lizards135 SpeciesHabitatSpecialized burrowersAfrica, South America, Caribbean, and Mideast

ReptiliaCharacteristicsLeglessWedge shaped headSingle median tooth in upper jawCan move forward or backward

ReptiliaOrder CrocodiliaGreek - lizard21 speciesCrocodiles, alligators, gavials, and caimansHave existed for 170 million years

Reptilia

Reptilia

ReptiliaSnout is elongatedNostrils at the anterior end to help with breathing while mostly submergedBreathe and inhale water at the same time

ReptiliaTailMuscular, elongated, and laterally compressedUsed for swimming, attacking prey, and maneuvers

ReptiliaTeethLaterally compressed teethThrashing motion of captureSwallow food wholeDeath roll StomachGizzard-likeSwallow rocks and other objects

ReptiliaReproductionOviparousParental Care resembles that of birdsNesting and parental care can be traced to common ancestor of both groups

ReptiliaExternal StructuresSkin No respiratory functionThick, dry, and keratinized scalesShedding of the scales is called ecdysisPheromones are secretedCryptic, Aposematic, and mimicry coloration

ReptiliaSupport Skeleton resembles amphibian formSkull is elongatedSecondary palateIncrease in cervical vertebraeAtlas and axis increase head movementRibs can be highly modifiedCobraFlying lizardsAutotomy - loss of a tail

ReptiliaMovementPrehistoric ReptilesMany were bipedalReptileTetrapodsPrimitive reptiles move like salamandersHigher than most amphibians

ReptiliaNutrition and DigestionCarnivoresTongueTurtles and crocodiles are nonprotrusibleLizards and anurans have sticky tongues May exceed the lizards length

ReptiliaSnakes Glottis is far forward to allow for breathingVipers have hollow fangs that are hinged on the maxillaryCoral, sea, and cobra snakes rigid fangsSome cobras can spitVenom glands are modified salivary glands

ReptiliaBody RegulationGas ExchangeThree chambered heartSinous venosus is now a pacemaker

ReptiliaLow oxygenated blood from right atrium to ventricle High oxygenated blood from lungs to ventricle to left atrium

ReptiliaGas exchangeAcross respiratory surfacesPartitioned into spongelike chambersForm a negative pressure mechanism for ventilation

ReptiliaTemperature RegulationEctothermsCan survive (-2 to 41 oC) Need (25 to 37 oC) to liveBehavior is used for temperature regulationBody orientationNocturnalPantingBlood diversionChormatophore dispersion

ReptiliaNervous and Sensory FunctionsCerebral hemisphere is larger than in AmphibiansImproved smellJacobson organSnakes can smell with their tongueImproved vision motor coordinationEars detect vibrationsSnakes have heat sensitive pit organs

ReptiliaOptic lobe and Cerebellum are enlargedIncreased visionMore refined motor coordinationIndependent eye movementDifferent fields of visionDominant sense in most reptilesColored vision

ReptiliaExcretion Kidneys have more nephrons or blood filtering units (Metanephric kidneys)More blood flowHigher pressureExcrete uric acidInsoluble in waterCan be stored as a paste

ReptiliaOsmoregulationReabsorption of waterInternal respiratory surfacesRelatively impermeable exposed skinBehaviorNocturnalAvoidance of hot surfacesStorage of water in lymphatic spaces

ReptiliaReproductionEggsLand dwelling is possibleNot completely independent of water

ReptiliaInternal FertilizationEgg shell forms afterMales have an intromittent organSperm can be stored by the femaleTurtles 4 yearsSnakes 6 years

ReptiliaParthenogenesis 6 families of lizards1 family of snakeParental CareEggs are usually abandoned100 species of reptiles take care of their young American alligatorSex is temperature dependent