Class Reptilia: Reptiles

• Ex: Lizards, Snakes, Turtles & Crocodiles

Modern reptiles share 7 key characteristics…

Strong, bony skeletonEctothermic metabolism

Dry, scaly skinAmniotic egg

Respiration through lungsPartially divided heartInternal fertilization

Except for snakes, reptiles haveStrong bony skeletons with

Two pairs of limbs.

Their legs are positioned more under The body than amphibians whichSupport more weight and allow

Them to move about faster.

They also have toes with claws.

Reptiles’ ectothermic metabolismIs too slow to generate enough Heat to warm their bodies, so

They must absorb it from The environment.

Reptiles have evolved a practicallyWater tight skin of scales.

The scales are flexible and overlap.

This has allowed reptiles to leave The water and live on land.

Since reptiles live on dry land, theyCannot have the same eggs as

Fish and amphibians.

Reptiles developed a water tight eggThat has its own supply of

Food and water

All land animals have developed An efficient set of lungs.

Reptiles, and future animals,Have lungs with thousands of Alveoli on the inner surface.

They also have a strong set of Muscles to draw more air in

And out of the lungs.

LungsLungs

Reptiles have a partially dividedHeart that separates oxygen

Rich blood and oxygen poor blood.

Unlike fish and amphibians, reptile Eggs are fertilized internally.

This helps to protect the gametesFrom drying out on land.

Most reptiles are oviparous, they Lay eggs from which the

Young hatch.

A few are ovoviparous, which meansThat the eggs are kept insideThe female until they hatch.

There are 4 classes of reptiles.

In lizards and snakes, the lowerJaw is only loosely attached, so they

Can eat things much larger thanThe size of their mouth.

Lizards, Snakes, Crocs, & Turtles

Common lizards include iguanas, chameleons, and horned lizards.

Most are carnivores!

Most are smaller than your foot, but

A komodo dragon can get to be 10 feet and weigh 500 pounds!

Snakes probably evolved from Lizards during the Cretaceous period.

The skeleton of snakes has noRemnants of a pelvic girdle.

Some snakes strangle theirPrey and others have poisonous venom.

There are 4 types of poisonous snakes,Only one lives in this area,

The water moccasin.

Turtles and tortoises are unique Because of their shell.

They evolved about 200 Million years ago.

The carapace is the top part of the

Shell and the plastron is the bottom.

Crocodiles and alligators belongTo the class crocodilian.

Crocodiles have a longer thinnerSnout than alligators do.

American alligators can be 18 feetLong, but Nile Crocodiles can get20 feet and weigh 1600 pounds!

They are the only reptiles to careFor their young.

Class Aves: The Birds

• Ex. Woody Woodpecker, Roadrunner &

• Archaeopteryx.

All birds share the same 6 characteristics…

Forelimbs modified into wingsBody covered in feathers

Lightweight bonesEndothermic metabolism

Super-efficient respiratory systemHeart is completely divided

Feathers = thought to have evolved from scales

-like reptiles they molt-colored for camouflage or mating

• Types

a. contour- cover body and give shape

b. flight- contours on wings and tail -Provide lift for flight

c. down- soft, fluffy and provide insulation

Preening=

-preen gland

Strong, lightweight skeleton-thin and hollow

-may be fused (keel and collarbones)

Endothermic metabolism-heat through metabolism

-104° F to 108° F due to energy required of flight

Birds have a completely dividedHeart, just like you.

Highly efficient lungs -flight demands a lot of

energy -one way air flow

Specialized beak-no teeth or jaw

-gizzard takes over role of teeth -specialized to diet

Pg. 800

Specialized foot-specialized for lifestyle