CHAPTER 11 SECTION 4

Reptiles

What is a reptile?

EctothermVertebrate with lungs and scaly skin

Get oxygen from air (even sea turtles)Can spend entire life on landLay eggs on landExamples: snakes, lizards, turtles,

alligators

Adaptations

First vertebrates to adapt and live on landSkin

Dry, tough skin covered with scales Helps keep water in their bodies

Kidneys Organs that filter waste from the blood Waste is then excreted in a watery fluid called

URINE Kidneys concentrate urine so reptiles lose little

water

Adaptations

Eggs Internal fertilization Amniotic Egg

Egg with a shell and internal membranes that keep the embryo from drying out

Pores in shell let oxygen in and carbon dioxide out

The Amniotic Egg

Lizards and Snakes

Most reptiles alive today are lizards or snakesSkin covered with overlapping scalesShed skin/scalesWarm areasLizards: four legs, claws on toes, long tails,

external ears, movable eyelids, two lungsSnakes: no legs, no external ears, no eyelids,

one lung

Lizards/Snakes Obtaining Food

Few lizards = herbivoresMost lizards = carnivoresAll snakes = carnivores

Some snakes have venom glands attached to hollow teeth called fangs

Some snakes have long, curved teeth http://www.youtube.com/watch?v=Qy67XU6xEi8

Lizards/Snakes Movement

Lizards Walk or move

Snake Slithers, contracting and shortening bands

of muscle connected to their ribs/backbones

Alligators

Large, carnivorous reptiles that care for their young

Broad, round snoutsFew teeth visible when mouth is shutCarnivores, hunt at night

Crocodiles

Large, carnivorous reptiles that care for their young

Carnivores, hunt at nightPointed snouts, most teeth visible when

mouth is shut

Alligator and Crocodile Video Clips

http://video.nationalgeographic.com/video/animals/reptiles-animals/alligators-crocodiles/croc_american/

http://video.nationalgeographic.com/video/animals/reptiles-animals/alligators-crocodiles/alligator_protectinghatchlings/

http://video.nationalgeographic.com/video/animals/reptiles-animals/alligators-crocodiles/baby-mugger-crocodiles-predation/

Turtles

Live in fresh water, ocean, land

Land = “tortoise”Body covered by a

protective shell that includes the ribs and backbone

Some turtles can pull their head, legs, and tail inside their shell

Have sharp-edged beak instead of teeth

Carnivores and herbivores

Turtle Video Clips

http://video.nationalgeographic.com/video/news/animals-news/us-oil-spill-turtle-relocation-vin/

http://video.nationalgeographic.com/video/animals/reptiles-animals/turtles-and-tortoises/crittercam-seaturtles-missions-wcvin/

http://video.nationalgeographic.com/video/animals/reptiles-animals/turtles-and-tortoises/turtles-baby-predation/

Extinct Reptiles– The Dinosaurs

Became extinct 65 million years ago

Some dinosaurs might have been endotherms

Earliest vertebrates that had legs positioned directly beneath their bodies