ReptilesCH. 34.1

I. CharacteristicsA. Reptile means “one who crawls.”–The study of reptiles is called Herpetology.

B. They were the first vertebrates to make a transition to life on land.

C. Amniotic Egg [p.838]–The total life supporting system for them.

–The development of internal fertilization and the amniotic egg allowed them freedom from reproducing in water.

II. Adaptations for land life.

A. Amniotic Egg and Internal Fertilization

B. Waterproof Skin–Covered with scales.

–Protects the body.

–Prevents water loss.

C. Modified Limbs–Some have legs with toes or claws.

–Some have “suction cups” to help with movement.

D. Specialized Body Systems–Most have a 3-chambered heart.2 atria and 1 ventricle.

–Alligators and crocodiles have 4 chambers.

Reptiles are cold-blooded [cannot control their body temperature.]–Ectothermic

–Endothermic=

warm-blooded

III. Dinosaurs

A. The earliest reptiles.B. Have been extinct for millions of years.

C. Dinosaur means= “terrible lizard.”

D. Most believe that a drastic climate change caused extinction.

IV. Modern ReptilesA. Crocodiles and

Alligators1. Live in or near water.2. Are carnivores.3. Their only enemy is

man.

Alligators have a broad, round snout.

Alligators are found only in the SE U.S. and a small area of China.

Crocodiles have a long, tapered snout.–Their teeth stick out from the bottom when the mouth is closed.

Crocodiles are found in the U.S., Africa, and Asia.

Is it a Florida Gator……or a Florida Crocodile????????

B. Turtles and Tortoises

Turtles live in or around water.

Tortoises live only on land.Both DO NOT have teeth,

but have a strong, sharp beak.

Snapping Turtle

There are:–Carnivores{meat}

–Herbivores{plants}

–Omnivores{both}

Tortoise

C. LizardsTwo species are poisonous:–1. Gila Monster

–SW U.S.

–2. Beaded Lizard–W Mexico

Some change colors to blend in with the environment.

Some can alter their body to appear fierce.

Chameleon

Frilled Lizard

Some lose their tail as a means of defense and regenerate a new one, this is called AUTONOMY.

The largest lizard is the Komodo dragon.

Tutuara

D. Snakes1. Most snakes move in

an “S”pattern.2. Eyesight and hearing are

not well developed…the sense of smell is the strongest.

3. Jacobson’s Organ

a.Two specialized pits in the roof of its mouth.

b.gathers chemicals from the air.

c.used to smell for prey.

Have a special hinged jaw that allow them to swallow prey much larger than the size of their own head.

They “unhinge” the jaw.

E. Two Categories of snakes:

1. NonpoisonousEx. King snake, boa constrictor, rat snake.

–a. some hold prey to the ground and swallow it LIVE.

–b. some squeeze it until it suffocates.

BOA CONSTICTOR

2. PoisonousEx. Rattlesnakes, cobras

–a. kill prey with poison injected with fangs {hollow teeth like hypodermic needles}.

Cottonmouth

Copperhead

Rattlesnake

b. Two Groups of Poisonous Snakes

1. Elapids–Small, tube-like fangs that are ALWAYS “erect”.Coral snakes, cobras

2. Pit Vipers–Have large fangs that fold up in the mouth when not being used.

Have an organ between the nostril and eye called a pit.

It is a “heat-sensing” organ to find warm blooded prey.

G. Four Poisonous Snakes in AL:

1. Copperhead–Pit viper

2. Rattlesnake–Pit viper

3. Water moccasin

{Cottonmouth}–Pit viper

4. Coral–elapid

BE SAFE!

RED on BLACK, friend to Jack…King snake.

RED on YELLOWYELLOW, kill a fella…coral.

H. Two Types of Poison:1. Hemotoxin

–Destroys blood cells and alters clotting {pit vipers}.

2. Neurotoxin–Affects the normal function of

the nervous system, that causes difficulty in breathing and heart function {elapids}.

3. There are more than 2,000 species of snakes, only about 125 are poisonous.

I. ReproductionA. Use a sense of smell

to find a mate.B. Internal fertilization.C. No parental care is

given; newborns defend themselves.

J. Types of Births:A. Oviparous

–Young hatch from eggs outside their mother’s body.Most reptiles

B. Ovoviviparous

Young hatch from eggs kept inside their mother’s body, BUT receive no nourishment from her during development.–Other reptiles

C. ViviparousYoung are born alive and

receive nourishment from the mother during development.–mammals

The End