1 reptiles. 2 key features of reptiles 1.strong, bony skeletons and toes with claws 2.two pairs of...
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ReptilesReptiles
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Key features of ReptilesKey features of Reptiles
1.1. Strong, bony skeletons and toes Strong, bony skeletons and toes with with clawsclaws
2.2. Two pairs of limbs, except Two pairs of limbs, except snakessnakes
3.3. Legs positioned vertically for Legs positioned vertically for support of body and movement support of body and movement on landon land
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External Structural External Structural Adaptations for LandAdaptations for Land
1.1. ClawsClaws-aid in climbing, -aid in climbing, digging and movement digging and movement in various terrainsin various terrains
2.2. Toes modified into Toes modified into suctions cupssuctions cups aid in aid in climbingclimbing
3.3. Absence of limbs Absence of limbs Snakes use scaly Snakes use scaly
skin and highly skin and highly developed skeletal developed skeletal and muscular and muscular systems to movesystems to move
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Ectothermic MetabolismEctothermic Metabolism
1.1. Regulate their temperature by Regulate their temperature by basking in the sun or seeking basking in the sun or seeking shadeshade
2.2. Become sluggish in very cold Become sluggish in very cold temperaturestemperatures
3.3. Intolerance to cold limits their Intolerance to cold limits their geographic rangegeographic range
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Temperature RegulationTemperature Regulation
Regulate their temp Regulate their temp by behaviorby behavior
Bask in sun to Bask in sun to speed up speed up metabolismmetabolism
Hide in shade Hide in shade to prevent to prevent overheating overheating
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Reptiles ContinuedReptiles Continued1.1. Dry, scaly skin, almost watertightDry, scaly skin, almost watertight
2.2. Amniotic eggs, almost watertightAmniotic eggs, almost watertight Contains a water and food supplyContains a water and food supply
3.3. Respiration through well developed lungsRespiration through well developed lungs Grape shaped chamber called Grape shaped chamber called alveolialveoli Alveoli increase the respiratory Alveoli increase the respiratory
surface area for gas exchangesurface area for gas exchange Strong muscles in rib cage help to Strong muscles in rib cage help to
move air in and outmove air in and out
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RespirationRespiration
Well developed Well developed lungslungs Tissues Tissues
involved in gas involved in gas exchange are exchange are located inside located inside bodybody
Kept moist in Kept moist in even in the even in the driest driest environmentsenvironments
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HeartHeart1.1. Ventricle of heart partly divided by a Ventricle of heart partly divided by a
septumseptum
2.2. Still incomplete separation of Still incomplete separation of oxygen-rich and oxygen-poor bloodoxygen-rich and oxygen-poor blood
3.3. Crocodiles and alligators Crocodiles and alligators
have a ventricle that is totally have a ventricle that is totally separated into two pumping separated into two pumping chamberschambers
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CirculationCirculation
Double loop circulationDouble loop circulation
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ReproductionReproduction1.1. Internal fertilizationInternal fertilization
2.2. Many reptiles are oviparous-young Many reptiles are oviparous-young hatch from eggshatch from eggs
3.3. Some lizards and snakes are Some lizards and snakes are ovoviviparous-female retains eggs in ovoviviparous-female retains eggs in her body until shortly her body until shortly
before hatching or hatching before hatching or hatching
may occur inside her bodymay occur inside her body
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Excretion Excretion
Conserve water by excreting Conserve water by excreting nitrogenous wastes in dry or pasty nitrogenous wastes in dry or pasty form as crystals of uric acidform as crystals of uric acid
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11stst Orders of Reptiles Orders of ReptilesSquamataSquamata
Snakes and lizardsSnakes and lizards lower jaw is loosely connected lower jaw is loosely connected
to skull allowing mouth to open to skull allowing mouth to open wide to accommodate large wide to accommodate large preyprey
Lizards can regenerate tail, but Lizards can regenerate tail, but will not have vertebraewill not have vertebrae
Molting occurs in bothMolting occurs in both
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SquamataSquamata1.1. Order consists of 5,640 species of Order consists of 5,640 species of
lizards and snakeslizards and snakes2.2. Loosely jointed upper jaw and Loosely jointed upper jaw and
paired reproductive organs in paired reproductive organs in malesmales
3.3. Lizards-presence of limbsLizards-presence of limbs4.4. Common lizards- iguanas, Common lizards- iguanas,
chameleons, skinks and geckoschameleons, skinks and geckos5.5. Live everywhere except AntarcticLive everywhere except Antarctic6.6. Special adaptations- agility and Special adaptations- agility and
camouflagecamouflage7.7. 2 species are venomous- Gila 2 species are venomous- Gila
monster (SW U.S.) and beaded monster (SW U.S.) and beaded lizard (western Mexico)lizard (western Mexico)
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1.1. Blend with Blend with background background chameleons- remain chameleons- remain inconspicuous inconspicuous
2.2. Horned lizards- Horned lizards- spiked armor,when spiked armor,when disturbed they disturbed they inflate,hiss and squirt inflate,hiss and squirt blood from eyesblood from eyes
3.3. Skinks and geckos- Skinks and geckos- lose their tails and lose their tails and regenerate-escape regenerate-escape from predatorsfrom predators
4.4. Most lizards are Most lizards are small- .3m in length; small- .3m in length; iguanas- 1m in lengthiguanas- 1m in length
5.5. Largest lizards- Largest lizards- monitors- Komodo monitors- Komodo Dragon (Indonesia) Dragon (Indonesia) 3m (9.8 ft) in length, 3m (9.8 ft) in length, 140 kg (308.6 lbs)140 kg (308.6 lbs)
Squamata Continued
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Adaptations of SnakesAdaptations of Snakes
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MovementMovement
1.1. A snake has a backbone A snake has a backbone of 100 to 400 vertebrae, of 100 to 400 vertebrae, with a pair of ribs with a pair of ribs attached attached
2.2. Provides the framework Provides the framework for thousands of musclesfor thousands of muscles
3.3. Interaction of bones, Interaction of bones, muscles, and skin muscles, and skin enables a snake to move enables a snake to move various ways:various ways:
Example:Example: side windingside winding
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FeedingFeedingSnakes eat animals, but lack Snakes eat animals, but lack
structural adaptations common to other structural adaptations common to other carnivorescarnivores
Snakes do not see or hear well, have no Snakes do not see or hear well, have no limbs, and teeth and small mouth cannot rip limbs, and teeth and small mouth cannot rip and grind fleshand grind flesh
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Locating PreyLocating Prey 1.1.Snakes evolved a sense of smell Snakes evolved a sense of smell
which they use to locate their prey which they use to locate their prey 2.2.Flicks its forked tongue to gather Flicks its forked tongue to gather
chemicals from the environment chemicals from the environment 3.3.Transfers chemicals to two pits in Transfers chemicals to two pits in
the roof of the mouth-the roof of the mouth-Jacobsons Jacobsons organorgan where nerves are highly where nerves are highly sensitive to the chemicalssensitive to the chemicals
4.4.Some snakes inject Some snakes inject toxic venomtoxic venom by by biting with fangs and injectingbiting with fangs and injecting
5.5.HemotoxinsHemotoxins-attack the circulator -attack the circulator system-disrupt the clotting of system-disrupt the clotting of blood. blood.
6.6.NeurotoxinsNeurotoxins-disrupting the nerve -disrupting the nerve pathways-dangerous to respiratory pathways-dangerous to respiratory and heart functions.and heart functions.
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Reproduction Reproduction
1.1. Most male snakes Most male snakes rely on the scent of rely on the scent of female snakes of heir female snakes of heir own speciesown species
2.2. Before mating, a male Before mating, a male and female snake and female snake may glide alongside may glide alongside by side, with the male by side, with the male stroking the female stroking the female with his chin and with his chin and flicking his tongue flicking his tongue over her body over her body
3.3. Fertilization is Fertilization is internalinternal
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Reproduction ContinuedReproduction Continued1.1. Most snakes are Most snakes are
oviparousoviparous2.2. Female lays eggs that Female lays eggs that
hatch outside her bodyhatch outside her body3.3. To break out a hatchling To break out a hatchling
uses a special tooth uses a special tooth which is lost soon afterwhich is lost soon after
4.4. Other snakes are Other snakes are ovoviviparous ovoviviparous
5.5. Female carries the eggs Female carries the eggs in her body in her body throughout development throughout development
6.6. Young are born liveYoung are born live7.7. All newborns must fend All newborns must fend
for themselves, relying for themselves, relying on their many on their many specialized adaptations specialized adaptations for survival on landfor survival on land
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Defense Defense 1.1. Natural selection resulted in modifications for Natural selection resulted in modifications for
defense.defense.2.2. Camouflage is beneficial for both seeking prey Camouflage is beneficial for both seeking prey
and hiding from predators. and hiding from predators. 3.3. Many snakes are green and blend with foliageMany snakes are green and blend with foliage4.4. Others are brown and hide against the bark of Others are brown and hide against the bark of
treestrees
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Swallowing and Digesting Swallowing and Digesting PreyPrey
1.1. A snakes upper and A snakes upper and lower jaws are lower jaws are hinged and move hinged and move independently. independently.
2.2. when unhinged, the when unhinged, the jaws stretch to allow jaws stretch to allow the mouth to open the mouth to open extremely wide. extremely wide.
3.3. While swallowing it While swallowing it whole the snake thrusts whole the snake thrusts its windpipe into the its windpipe into the throat, allowing the throat, allowing the snake to breathe snake to breathe
4.4. The process of can take The process of can take several hoursseveral hours
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Defense ContinuedDefense Continued
1.1. Some ward off Some ward off danger by rapidly danger by rapidly changing body changing body shapeshape
2.2. Extending a hood Extending a hood like cobras like cobras
3.3. Some hissSome hiss4.4. Others make Others make
mechanical noises mechanical noises 5.5. Such as the rattle Such as the rattle
of the rattlesnake.of the rattlesnake.
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22ndnd Order of Reptiles Order of ReptilesCheloniaChelonia
Turtles and tortoisesTurtles and tortoises Hard bony shell-dorsal Hard bony shell-dorsal
is carapace and is carapace and
ventral is plastronventral is plastron Lack teeth, but have beaksLack teeth, but have beaks Many herbivores but some are Many herbivores but some are
carnivorescarnivores
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CheloniCheloniaa
1.1. Order consists of about 265 Order consists of about 265 species of turtles and species of turtles and tortoisestortoises
2.2. Tortoise are terrestrial Tortoise are terrestrial 3.3. Turtles live in waterTurtles live in water4.4. Body covered by a shell made Body covered by a shell made
of hard plates- 2 parts- a of hard plates- 2 parts- a carapace and plastroncarapace and plastron
5.5. Retractable headRetractable head6.6. Forelimbs of a marine turtle Forelimbs of a marine turtle
have evolved into flippers and have evolved into flippers and freshwater turtles have freshwater turtles have webbed toeswebbed toes
7.7. Migratory behavior of sea and Migratory behavior of sea and river turtles river turtles
8.8. Returns to land to lay eggsReturns to land to lay eggs
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33rdrd Order of Reptiles Order of Reptiles CrocodiliaCrocodilia
Crocodiles and alligatorsCrocodiles and alligators Most closely related Most closely related
to dinosaursto dinosaurs Aggressive carnivoresAggressive carnivores Care for their young after Care for their young after
hatchinghatching
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CrocodilianCrocodilian1.1. Order composed of 20 species Order composed of 20 species
of large lizard-shaped reptiles- of large lizard-shaped reptiles- crocodiles, alligators, caimans crocodiles, alligators, caimans and gavials and gavials
2.2. Crocodilians live in or near Crocodilians live in or near water in tropical/ subtropical water in tropical/ subtropical regions of the worldregions of the world
3.3. Crocodiles-nocturnal animals; Crocodiles-nocturnal animals; Africa, Asia and AmericasAfrica, Asia and Americas
4.4. Alligators-China and southern Alligators-China and southern U.S.U.S.
5.5. Caimans-Central America, some Caimans-Central America, some in Floridain Florida
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1.1. CarnivorousCarnivorous
2.2. Eyes on head, Eyes on head, nostrils on top of nostrils on top of snout snout
3.3. See and breathe See and breathe while in waterwhile in water
4.4. Parental care- Parental care- both parents both parents care for young care for young by carrying in by carrying in jaws until jaws until developmentdevelopment
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44thth Order of Reptiles Order of ReptilesRhynchocephaliaRhynchocephalia
TuatarasTuatarasTwo species native to Two species native to
New ZealandNew ZealandMost active at low Most active at low
temperaturestemperatures
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RhynochocephaliaRhynochocephalia1.1. Only living species-New Only living species-New
ZealandZealand2.2. Resembles a large Resembles a large
lizard about 60 cm longlizard about 60 cm long3.3. Parietal eye-Parietal eye-functions functions
as a thermostat-as a thermostat-protects from protects from overheatingoverheating
4.4. Active at low Active at low temperatures, feed at temperatures, feed at night on insects, worms night on insects, worms and small animalsand small animals
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310 million 310 million years ago… years ago… reptiles were reptiles were the the first first vertebrates to vertebrates to make the make the complete complete transition to transition to life on landlife on land Limited competition for Limited competition for
the insects and plants the insects and plants that could be used as that could be used as food on the landfood on the land
An increase in An increase in competition for food competition for food and space among all and space among all the life-forms in the life-forms in aquatic environments aquatic environments
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Adaptations to Adaptations to LandLand
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Adaptations to Adaptations to LandLand
AAmnioticmniotic Egg EggLegsLegsLungsLungsScales or platesScales or plates
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AAmnioticmniotic Egg Egg
5.5. AllantoisAllantois stores the nitrogenous wastes stores the nitrogenous wastes produced by the embryo until the egg hatchesproduced by the embryo until the egg hatches
1.1. An egg with a An egg with a protective membrane protective membrane and a porous shell and a porous shell enclosing the enclosing the developing embryodeveloping embryo
2.2. Egg forms a Egg forms a “nursery”“nursery” to protect the embryoto protect the embryo
3.3. Egg derives its name Egg derives its name from the from the amnionamnion, the , the thin membrane thin membrane enclosing the salty enclosing the salty fluid in which the fluid in which the embryo floatsembryo floats
4.4. Yolk sacYolk sac encloses the encloses the yolk, a protein rich yolk, a protein rich food supply for the food supply for the developing embryodeveloping embryo
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1.1. The chorion regulates The chorion regulates the exchange of oxygen the exchange of oxygen and carbon dioxideand carbon dioxide between the egg and the between the egg and the outside environmentoutside environment
2.2. Amniote egg is Amniote egg is surrounded by a surrounded by a leathery shellleathery shell that may that may be hard in some species be hard in some species (Birds) because of the (Birds) because of the presence of calcium presence of calcium carbonatecarbonate
3.3. The male places the The male places the sperm inside the female sperm inside the female before the shell is before the shell is formed. This is called formed. This is called internal fertilizationinternal fertilization, , makes water transport makes water transport of sperm unnecessaryof sperm unnecessary
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Origin and Origin and EvolutionEvolution
From the studies of From the studies of fossils and fossils and comparative comparative anatomy, biologists anatomy, biologists infer that reptiles infer that reptiles arose from a group arose from a group of ancestral reptiles of ancestral reptiles called cotylosaurs, called cotylosaurs, which lived about which lived about 310 million years 310 million years ago.ago.
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The End