section 4. reptile: ◦ ectothermic vertebrate that has lungs and scaly skin types of reptiles:...
TRANSCRIPT
Section 4
Reptile: ◦ Ectothermic vertebrate that has lungs and scaly
skin
Types of Reptiles:◦ Snakes, lizards, turtles, and alligators
Background◦ Can spend their entire life on
dry land
◦ 1st vertebrates that are well adapted to life on land
◦ Dominant land species for 160 million years
◦ 7,000 kinds of reptiles are alive today
Adaptations to life on land ◦ Eggs
◦ Skin
◦ Kidneys
Adaptations help them conserve water
What type of fertilization do reptiles use?◦ Internal fertilization◦ Fertilized eggs are covered
with a membrane and a shell
The membrane and shell protect the embryo and prevent it from drying out
Amniotic Egg Information◦ Soft and leathery
◦ Tiny holes let oxygen in and carbon dioxide out
◦ Eggs can be laid on land
◦ 1 membrane holds the liquid that surrounds the embryo – keeps it from being crushed and keeps it moist
◦ 2nd membrane holds the yolk or food
◦ 3rd membrane holds the wastes
What type of skin did amphibians have?◦ Thin and moist
How is a reptiles skin different?◦ It is dry, tough, and covered with scales
What is the function of scales?◦ Protection◦ Conserve water in their body
What is the other organ that helps conserve water?◦ Kidneys
Kidneys filter out the waste from the blood
The waste from the blood is excreted in the urine
Concentrate their urine so much that they barely lose any water
Have a heart with 2 atria and 1 ventricle
Breathe entirely with lungs
2 loops for their blood to circulate◦ 1st blood travels from the heart to the lungs back to
the heart Becomes oxygenated
◦ 2nd loop travels from the heart to the tissues Oxygen moves out of the blood and into the tissues Then the blood returns to the heart
Live in warm areas
Have skin with overlapping scales
Shed their skin replacing worn scales with a new coat
Eating Habits◦ A few lizards are herbivores◦ Most are carnivores
Eat frogs, ground-dwelling birds, and insects
A Lizard’s Body◦ 4 legs and claws with toes◦ Long tails◦ Slender bodies◦ Moveable eyelids◦ External ears
Snake bodies:◦ Similar to lizards but streamlined
◦ No legs
◦ No eyelids
◦ No external ears
◦ Most have only 1 lung
Movement:◦ Contract bands of
muscles that are connected to their ribs and backbones
◦ Alternating contractions creates a slithering side-to-side motion
Eating:◦ All snakes are
carnivores
◦ They can spread their jawbones wide apart
◦ A snake’s skull can move to let the snake swallow an animal much larger in diameter than itself
Eating Cont’d:◦ Sharp-tailed snakes of W. North America
Hook their slippery prey
◦ West Indian Boas Snatch their prey out of the air
◦ Rattlesnakes and copperheads Venom glands
Reptile covered by a protective shell◦ Made from its ribs and backbone
Shell sizes and strengths vary◦ Examples on 108 in the reading
There are turtles that are carnivores while some are herbivores
Largest living reptiles◦ Spend most of their day resting in the sun or lying
in the water
How do you tell an alligator from a crocodile?◦ Alligators have a broad, rounded snout with only a
few visible teeth
◦ Crocodiles have a pointed snout and you can see most of their teeth
Carnivores that hunt at night
Strong, muscular tails to swim rapidly
Large, sharp teeth
Extremely strong jaw muscles
Usually do not attack humans
Care for their eggs and newly hatched young
After birth the mother scoops them into her mouth and carries them to a safer location
Typically females stay with the young for up to a year
225-65 million years ago reptiles were the major form of vertebrate
May have been endothermic
Have been extinct for 65 million years◦ Due to climate ◦ Huge meteorite