The New Childrens Encyclopedia

(Marvins-Underground-K-12) #1

LIVING WORLD


Animal life


There are more than 1.2 million identified species


of animal, making this the largest kingdom of


living things.


WHO’S WHO?
Most animals are invertebrates: they have no backbone. Animals with
backbones are known as vertebrates, and they can be divided up into
different classes.

 MAMMALS
There are more than
5,000 species of
mammal. What
makes this class
unique is that the
young feed on milk
from their mothers.
Mammals are
warm-blooded, most
have a hairy body,
and most give birth
to live young.

 BIRDS There are
about 9,500 species
of bird. They are
warm-blooded, have
wings and a bill, and
a body covered in
feathers. All birds
lay eggs and
most can fly.

 REPTILES
The 8,000 species of
reptile are recognized
by their scaly skin.
They are cold-
blooded and lay
eggs to reproduce.

 AMPHIBIANS
Most of the 6,000
species of amphibian
live part of their lives
in water and part
on land. They are
cold-blooded.

 FISH This is an
informal group of
three different classes,
which together have
29,000 species. All
fish are cold-blooded
and live in water.

 INVERTEBRATES
An informal grouping
of about 29 major
groups (phyla), the
invertebrates include
all those animals that
do not have a backbone.
Worms, insects, shrimps,
jellyfish, and octopuses
are all invertebrates.

Invertebrates


Vertebrates


BIGGEST, HEAVIEST, LOUDEST
At up to 100 ft (30 m) long, the blue whale is
easily the biggest animal on Earth. It’s also the
heaviest, weighing 135 tons (120 metric tons),
and the loudest. At 188 decibels, its calls are
louder than a jet engine. A blue whale’s heart
is the size of a small car and its largest blood
vessel is wide enough for a small person to
crawl inside. Blue whales are threatened with
extinction due to overhunting in the past.

RECORD BREAKERS


 THOSE ARE ANIMALS?
It’s usually easy to tell an animal from a
plant—animals are the ones that move
around. But this isn’t always the case. Corals
look like plants and have limited movement.
However, they take in food to get energy and
they have nerves that control their reactions
(such as shrinking away from danger).
These things are what make them animals.

 SMALLEST
VERTEBRATE
Australia’s infantfish is less
than ½ in (1 cm) long.

 STRONGEST
The rhinoceros beetle
can lift 850 times its
own weight. If the
beetle weighed as
much as a human
it could lift at least
two fully loaded
double-decker buses.

Rhinoceros
beetle

LIVING WORLD


Leopard
tortoise

92
(c) 2012 Dorling Kindersley. All Rights Reserved.(c) 2012 Dorling Kindersley. All Rights Reserved.
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