The New Childrens Encyclopedia

Reptiles

Reptiles are cold-blooded vertebrates

that have tough skin covered in scales.

The scales are made of keratin—the same

material as mammal hair and bird feathers.

There are nearly 8,000 species of reptile,

grouped in four orders. The biggest order

is snakes and lizards.

Although some snakes and lizards give

birth to live young, most reptiles reproduce

by laying eggs. Some look like birds’

eggs—they have hard, rounded shells—but

most eggs have softer, leathery shells. The

hatchlings break through their shells using

a sharp “egg tooth,” which then falls out.

REPTILE EGGS

 LIZARD Leopard geckos lay a

clutch of two long, sticky eggs in their

underground burrows.

Panther chameleon

Furcifer paradalis

TAKE A PICTURE

A dione ratsnake (Elaphe dione) begins

“sloughing” its skin. Snakes shed their

skin up to eight times a year.

 SNAKE Young

snakes coil up tightly

inside a shell. Some

can be up to seven

times longer than

their egg.

TAKING A STAND

A reptile’s legs stick out at right

angles to its body (unlike

mammals’ and birds’, which

do not). This gives them a

very sturdy frame for walking

on uneven land.

 TORTOISE

Large tortoises and

turtles, such as leopard

tortoises, lay almost

perfectly round eggs.

FEARSOME FANGS

Some snakes have venom glands

just behind their fangs. Venom is

used to kill prey, and sometimes in

defense. Baring fangs is a warning

to attackers to back off.

Emerald tree boa (juvenile)

Corallus caninus

BENDING BACKBONE

A snake’s backbone is incredibly

flexible. Tree boas coil around

branches to rest and to spot

prey. Desert vipers squeeze

under rocks for shade.

Sidewinding snakes zip across

the ground in S-shaped waves.

102

Western diamondbacked

rattlesnake Crotalus atrox

LIVING WORLD

Thorny devil

Moloch horridus