Animal Classification

Scientists cannot seem to agree on whether there should be 5 or 6 kingdoms of living things. The argue over whether bacteria should be divided into one or two kingdoms.

Note: Students do NOT need to know this information for the test.

Examples in each of the six kingdoms.

Note: Students do NOT need to know this information for the test.

Note: Students do NOT need to know this for the test!!

How do we classify animals?When you classify, you arrange things into groups based on ways that they are

alike. Scientists grouped animals into classes to make it easier to study them.

All animals are divided into two main groups – vertebrates and invertebrates.

Vertebrates Invertebrates

VertebratesA vertebrate is an animal that has a spine or backbone. The

five most well known classes of vertebrates are birds, fish,

mammals, reptiles, and amphibians.

MammalsMammals are warm-blooded animals that feed their young with milk,

have fur or hair, and breathe air with lungs. Being warm-blooded means

the body temperature stays the same when it is cold or hot outside.

Examples of mammals include humans,

elephants, horses, whales, dogs, and giraffes.

Can you think

of more

mammals?

AmphibiansAmphibians are born in the water and breathe with gills like a fish.

When they grow up, they develop lungs and can live on land.

Most amphibians hatch from eggs.

After they hatch, they can only live under water like a fish

with gills to breathe and fins to swim with.

As they grow older, they undergo changes called metamorphosis.

They grow lungs to breath air and limbs for walking on the ground. 3

2

1

Amphibians are cold-blooded meaning their bodies don’t

automatically regulate their temperature. Their body temperature

depends on whether it is cold or hot outside.

There are more than 4000 different kinds of amphibians. Examples

include frogs, salamanders, newts, and frogs.

Frog

ReptilesReptiles are cold-blooded animals born on land. They have scaly

skin and they breathe using lungs. Most reptiles lay eggs.

Examples of reptiles include snakes, lizards, alligators, and turtles.

Our class pet gecko is a reptile.

BirdsBirds are the only animals that have feathers. They are warm-

blooded and have wings, a beak, and two legs. They also lay eggs.

Not all birds fly! Some birds that don’t fly are penguins and ostriches.

Fun Fact: An ostrich is so fast it can outrun a horse!

OstrichPenguin

FishFish are cold-blooded animals that live in water. They have gills to

help them breathe and scales to help them move through the water.

Scientists believe there are more than 24,000 species of fish in the world.

Examples of fish include catfish, stingrays, swordfish, lion fish, scorpion

fish, and sharks.

Catfish

Stingrays

Swordfish

Lionfish

Scorpion Fish

Shark

Can you think

of more types

of fish?

An invertebrate is

an animal that

does not have a

backbone. Over

96% of the world’s

animals are

invertebrates.

Invertebrates

Examples of invertebrates include butterflies, grasshoppers,

worms, spiders, starfish, and squid.