Grade-3 Social Science, Term-2 Chapter-8 Prehistoric Animals
Chapter-8
Prehistoric Animals
Fill
in the blanks
(photosynthesis, bacteria, Mesozoic,
turtles, crocodiles, eras, 4.5 billion, muscles or bones)
1. Life on the earth can be
divided into different phases called eras.
2. The first signs of life
were tiny bacteria in Pre-Cambrian Era.
3. The Earth is believed to
have formed 4.5 billion years ago.
4. Early bacteria carried out photosynthesis.
5. The first animals of
pre-cambrian era had soft bodies without muscles or bones.
6. Mesozoic era saw the emergence of
dinosaurs.
7. Dinosaurs, turtles, crocodiles,
frogs and the first birds lived at the same time.
Name
a prehistoric
- Flying
reptile
Pterodactyl-
Pteranodon
- Swimming
creature
Ichthyosaur
- Plant
Fern
- Dinosaur
Stegosaurus
Give
two examples of prehistoric animals that lived
- Before
dinosaurs
(trilobites, eel like
fish, giant spiders, ancestors of shark)
- Along with
dinosaurs
(turtles, crocodiles,
frogs, first birds)
- After
dinosaurs died
(snakes, mammoth, monkeys
and apes)
Give
reason
There
were no flowers or grasses in the early parts of the mesozoic era.
In
the early parts of the mesozoic era, there were no flowers or grasses because
the earth was hot and dry.
Dinosaurs
are extinct.
Dinosaurs
are extinct because probably-
1. A giant rock from space may
have hit them
2. The climate changed and
they were not able to adjust/adapt.
3. A disease struck them- they
fell sick and died
Answer
in one word
1. Ankle-length plant of
Paleozoic Era having leafless branching stems with rounded tips.
Cooksonia
2. Dinosaurs rules during this
era.
Mesozoic Era
3. Dinosaurs became extinct in
this era.
Cenozoic Era
4. An animal that looked like
a big hairy elephant and had long tusks.
Mammoth
5. A prehistoric bird.
Archaeopteryx
6. A prehistoric animal that
had hard shells.
Trilobites
7. An animal which was
probably the ancestor of modern lions and tigers.
Sabre-toothed cat
8. An insect that has been
there since prehistoric times.
Cockroach
9. A dolphin-like giant marine
animal that lived in the Mesozoic Era.
Ichthyosaur
10. A flying reptile having
wing-span of 6 to 7 metres, having boneless beak and crest on the head.
Pteranodon
11. A carnivorous dinosaur that
was about the size of a dog.
Eoraptor
12. A flying, carnivorous
dinosaur that had featherless wings.
Pterodactyl
13. Dinosaur that had a head
like a crocodile and is known to have eaten fish.
Baryonyx
14. One of the largest
carnivorous dinosaurs that weighed around eight tonnes and hunted in packs.
Giganotosaurus
15. One of the largest
herbivorous dinosaurs, having a very long neck, walked on four legs and is
called the 'gentle giant’.
Apatosaurus
16. A herbivorous dinosaur that
had spikes along its back and tail and it walked on four legs.
Stegosaurus
17. A herbivorous dinosaur that
had a bony frill and horns like a rhinoceros, having three big horns in its
large head.
Triceratop
18. A herbivorous dinosaur
having long spikes on its thumbs.
Iguanodon
19. A large and strong
herbivorous dinosaur having an eight metres long neck and a small brain.
Diplodocus
20. One of the tallest
herbivorous dinosaurs with a very long neck and the height of a four-storey
building.
Brachiosaurus
21. An omnivorous dinosaur that
had very good vision, an intelligent brain and it rained on two legs.
Troodon
Answer these questions:
Q.
What do you understand by prehistoric period?
Ans-
The period of history about which there are no written records, is called
the Prehistoric period.
Q.
If there was no written record of prehistoric times, how do we know about the
animals and people who lived then?
Ans-
We know about the animals and people who lived from
1)
paintings in caves
2)
objects used by people in those days
3)
bones and fossils of animals and plants.
Q.
What are fossils?
Ans-
Fossils are unspoilt remains of prehistoric plants and animals and the
Impressions or marks left by them when they were caught in mud or rock.
Q.
What can we know from the bones of a dinosaur?
Ans-
From the bones of a dinosaur we learn-
1. its behaviour and
appearance
2. Weather it was primitive or
advanced dinosaur
3. Whether it ate plants or
meat
4. Whether it had small or
large brain
5. It had good or bad eyesight
6. About hearing and sense of
smell
7. What other Dinosaurs it was
related to
8. Lifestyle and habits
Q.
How did animals on Earth change?
Ans-
Animals on Earth changed because of the change in climatic conditions and
adaptations in a process called evolution.
Q.
What is a dinosaur? What does it mean?
Ans-
Dinosaurs are a diverse group of prehistoric reptiles. The word dinosaur means
“terrible lizard”.
Q.
Describe dinosaurs.
Ans-
The word dinosaurs means “terrible lizards”. They can be described as:
1. While some were small, most
were very large and heavy creatures.
2. Large bones
3. Sharp claws and teeth.
4. Leathery-scaly skin that
made them look terrifying.
5. Many walked on four legs
while somewhat on two.
6. Huge animals with small
brains
7. Laid eggs like birds
8. Mostly herbivores or
carnivores. Some were omnivore
Q.
When did dinosaurs roam the earth?
Ans- Dinosaurs first appeared 247 million years ago. They
ruled the Earth for about 175 million years until an extinction event 65.5
million years ago wiped out all of them, expect for the avian dinosaurs.
Q.
What did dinosaurs eat?
Ans- Some dinosaurs ate lizards, turtles, eggs, or early
mammals. Some hunted other dinosaurs or scavenged dead animals. Most, however,
ate plants (but not grass, which hadn't evolved yet).
Q.
In which period of the Mesozoic era, forests came into existence and why?
Ans-
In the Jurassic period of the Mesozoic era, forests came into existence as more
oceans were formed and rain became heavier.
Q.
What happened to the dinosaurs by the time man evolved?
Ans-
The dinosaurs became extinct by the time man evolved.
Q.
Describe some prehistoric animals that lived alongside the dinosaurs.
Ans-
Turtles, crocodiles, frogs and first birds lived alongside the dinosaurs. There
were also mammals at the same time.
Q.
Which prehistoric animals lived alongside early man?
Ans-
These prehistoric animals lived alongside early man-
1. Mammoths
2. Giant ground sloth
3. Dire wolves
4. saber-toothed
cats
5. Monkeys
6. Apes
Q.
Give the names of some animals of today that lived in prehistoric times.
Ans-
Following are the animals of today that lived in prehistoric times:
1. Sponges
2. Snails
3. Spiders
4. Sharks
5. Jellyfish
6. Coral
7. Cockroaches
8. Apes
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