Dinosaurs disappeared from the Earth approximately 65 million years ago. There are many theories about what happened to them. So far, no one can prove why these powerful creatures suddenly disappeared. It may remain a mystery forever.
Some scientists believe that a huge asteroid from space hit the Earth. The impact and the heat from the asteroid could have killed the dinosaurs. Others believe that the asteroid gave off too much gas in the Earth’s atmosphere. This gas may have blocked rays from the sun. The cooler temperatures could have started an ice age. The low temperatures could have been too cold for the dinosaurs.
Another theory is that a gradual change in climate occurred for thousands of years. Scientists believe that winters became too cold. Summers became too hot for the dinosaurs to survive. Without fur or feathers, dinosaurs could not keep themselves warm in winter. They would have also had a hard time keeping cool in summer.
The truth is, we might not ever know what happened. It is a mystery.
1.When did dinosaurs disappear?
a few thousand years ago
about 15 billion years ago
less than 1 million years ago
about 65 million years ago
2.Because no one is sure why dinosaurs went extinct,
scientists all believe an asteroid killed them.
the dinosaurs may all still be alive today.
there is no chance that humans could ever go extinct.
people have come up with theories to try to explain it.
3.Based on the passage, it can be understood that
there is not enough evidence to prove the extinction theories.
scientists will definitely figure out the cause of dinosaur extinction at some point.
most scientists believe the ice age theory of extinction.
there are many hundreds of different extinction theories.
4.Read the following sentence: “Another theory is that a gradual change in climate occurred for thousands of years.”The word gradual means
over a long period of time
related to plants
5.The main idea of this passage is
no one knows how the dinosaurs became extinct.
an asteroid may have hit the Earth millions of years ago.
dinosaurs could not adapt to changing temperatures.
scientists are trying hard to find out why dinosaurs became extinct.
6.Explain one of the theories in the passage for what caused the extinction of dinosaurs.
7.Based on the passage, explain what might have happened to dinosaurs if the temperatures had never changed.
8.The question below is an incomplete sentence. Choose the answer that best completes the sentence.It became too cold on Earth, ________ dinosaurs became extinct.
The videos and activity for this session can be found here.
Have a look at both videos and make sure you have a pencil and paper handy in case you need to work anything out or draw it.
This is a really important skill to master. It’s all about division. The main things to remember are that, if you are simplifying a fraction:
– The numbers in the fractions will become smaller
– you MUST divide the numerator and denominator by the same number to simplify it.
Dinosaurs are a group of reptiles that lived long ago. The first dinosaurs walked the earth about 245 million years ago. For millions of years, they lived and thrived. Then, about 66 million years ago, the dinosaurs were wiped out when a huge event destroyed much of life on Earth. But scientists today are still able to learn about these interesting animals. They learn about them by studying what remains of the dinosaurs – fossils.
A fossil is any evidence of life from long ago that is at least 10,000 years old. A fossil can be what’s left of the bones or teeth of an animal. It can also be a footprint left behind by an animal. But fossils are not just remains of animals. They can also be remains of plants, like the impression of a fern left in a rock.
Have you ever seen a picture of a dinosaur skeleton in a museum? The dinosaur bones you can see in a museum are actually fossils. But how did these fossils form from the dinosaur’s bones? This happened over millions of years, through a process called fossilization. When the dinosaur those fossils came from died, it may have been buried by sediments like sand and silt. As the dinosaur’s body rotted, these sediments protected the bones from rotting. After many years, only the hard parts of the body were left behind. Over millions of years, the water in the rocks nearby surrounded those hard parts. Over time, the minerals in the water replaced the hard parts. So after millions of years, what was left was a solid rock copy of the dinosaur’s bones – the fossils.
Scientists called paleontologists study dinosaur fossils to learn more about dinosaurs. They can learn about how dinosaurs lived, moved, ate, grew, and more by studying fossils. For example, they can look at the shapes and sizes of a dinosaur’s teeth to see what kinds of food it most likely ate. They can study fossilized footprints to learn about how quickly a kind of dinosaur may have moved. And they can draw conclusions about how some dinosaurs behaved by studying some fossilized dinosaur eggs and nests.
1.Dinosaurs are a group of reptiles that lived long ago. When did they first walk the earth?
66 million years ago
1oo million years ago
245 million years ago
45 million years ago
2.What does the text describe?
how scientists find and store fossils
the process by which fossils form
the huge event which destroyed much of life on Earth
the ecosystems in which dinosaurs lived
3.Read the following sentences from the text.
Scientists called paleontologists study dinosaur fossils to learn more about dinosaurs. They can learn about how dinosaurs lived, moved, ate, grew, and more by studying fossils. For example, they can look at the shapes and sizes of a dinosaur’s teeth to see what kinds of food it most likely ate. They can study fossilized footprints to learn about how quickly a kind of dinosaur may have moved.
Which conclusion does this information best support?
Fossils can help us learn what living things from long ago were like.
Fossils can help us understand how living things are currently changing.
Fossils can help us come up with cures to diseases different living things face.
Fossils can help us predict when there will be another huge event that will change earth.
4.Based on the text, what can be concluded about the area in which a fossil is found?
It has stayed the same throughout the years.
It has harmed animals that get close to the area.
It has erased all signs of living things from long ago.
It has changed throughout the years.
5.What is the main idea of this text?
About 66 million years ago, dinosaurs were wiped out when a huge event destroyed much of life on Earth.
Dinosaur fossils, or remains, formed over millions of years and can help scientists learn about these animals.
Scientists can look at the shapes and sizes of a dinosaur’s teeth to see what kinds of food it most likely ate.
A fossil can be what’s left of the bones or teeth of an animal, or it can also be a footprint left behind by an animal.