What is a Dinosaur?
Dinosaurs were reptiles that lived on Earth millions of years ago. They
first evolved on Earth around 230 million years ago, in a time called
the Mesozoic Era, which was made up of three time periods; the
Triassic period, the Jurassic period and the Cretaceous period.
The Mesozoic Era is known as the ‘age of reptiles’. The dinosaurs ruled
the Earth for over 160 million years!
All dinosaurs
had several features
in common...
Eggs
All dinosaurs laid eggs.
Skull Holes
Their skulls had large holes or
‘windows’ which made them lighter,
which was important as some of the
biggest skulls were as big as a car!
Special types of scientists called
Palentologists study old bones and
fossils that were left behind on
Earth when the dinosaurs died
out, and they have discovered lots
about dinosaurs and how they lived.
vores
were either herbi
Al dinosaurs
lant life
s. Herbivores ate p
or carnivore
saurs
res ate meat. Dino
and carnivo
were
y different, some
al looked ver
se, and
igger than a hou
huge and b
use cat!
smal er than a ho
others were
o legs,
urs walked on tw
Some dinosa
s.
others on four leg
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Legs
All dinosaurs, whether they had two
or four legs, walked on their toes
with their legs directly underneath
their bodies.
Scaly skin
Although scientists cannot know
the colour of dinosaurs’ skin, as
impressions of dinosaur skin are
rare, they have found enough to
know that dinosaurs had scaly skin.
Claws
Meat eating dinosaurs had sharp,
hooked claws on their toes and
plant eating dinosaurs had blunt
toenails or hooves.
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