Fossils and Dinosaurs The Extinction of Dinosaurs

Transcription

1 Non-fiction: Fossils and Dinosaurs The Extinction of Dinosaurs Fossils and Dinosaurs The Extinction of Dinosaurs 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 1. 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 atmosphere: the mass of air surrounding the Earth 1

2 Questions: Fossils and Dinosaurs The Extinction of Dinosaurs Name: Date: 1. When did dinosaurs disappear? a. a few thousand years ago b. about 15 billion years ago c. less than 1 million years ago d. about 65 million years ago 2. Because no one is sure why dinosaurs went extinct, a. scientists all believe an asteroid killed them. b. the dinosaurs may all still be alive today. c. there is no chance that humans could ever go extinct. d. people have come up with theories to try to explain it. 3. Based on the passage, it can be understood that a. there is not enough evidence to prove the extinction theories. b. scientists will definitely figure out the cause of dinosaur extinction at some point. c. most scientists believe the ice age theory of extinction. d. 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 a. unimportant b. over a long period of time c. accidental d. related to plants 5. The main idea of this passage is a. no one knows how the dinosaurs became extinct. b. an asteroid may have hit the Earth millions of years ago. c. dinosaurs could not adapt to changing temperatures. d. scientists are trying hard to find out why dinosaurs became extinct. 2

3 Questions: Fossils and Dinosaurs The Extinction of Dinosaurs 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. a. because b. so c. after d. but 9. Read the following sentence. Dinosaurs disappeared from the Earth 65 million years ago because of major changes that happened. Answer the questions below based on the information provided in the sentence you just read. One of the questions has already been answered for you. 1. What? dinosaurs 2. What did dinosaurs do? 3. When? 4. Why? 3

4 Questions: Fossils and Dinosaurs The Extinction of Dinosaurs 10. Vocabulary Word: atmosphere: the mass of air surrounding the Earth. Use the vocabulary word in a sentence: 4

5 Answers: Fossils and Dinosaurs The Extinction of Dinosaurs Passage Reading Level: Lexile 670 Teacher Guide and Answers Featured Text Structure: Cause/Effect the writer presents the reason an event happened and its results Passage Summary: This passage describes some explanations of what may have caused dinosaurs to disappear 65 million years ago. 1. When did dinosaurs disappear? a. a few thousand years ago b. about 15 billion years ago c. less than 1 million years ago d. about 65 million years ago 2. Because no one is sure why dinosaurs went extinct, a. scientists all believe an asteroid killed them. b. the dinosaurs may all still be alive today. c. there is no chance that humans could ever go extinct. d. people have come up with theories to try to explain it. 3. Based on the passage, it can be understood that a. there is not enough evidence to prove the extinction theories. b. scientists will definitely figure out the cause of dinosaur extinction at some point. c. most scientists believe the ice age theory of extinction. d. 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 a. unimportant b. over a long period of time c. accidental d. related to plants 5

6 Answers: Fossils and Dinosaurs The Extinction of Dinosaurs 5. The main idea of this passage is a. no one knows how the dinosaurs became extinct. b. an asteroid may have hit the Earth millions of years ago. c. dinosaurs could not adapt to changing temperatures. d. 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. Suggested answer: One theory is that a huge asteroid from space hit the Earth, causing the extinction of dinosaurs. Another is that an ice age began and it was too cold. Another is that a changing climate made summers too hot. 7. Based on the passage, explain what might have happened to dinosaurs if the temperatures had never changed. Suggested answer: Answers will vary. Students should say either that dinosaurs would not have gone extinct or that the impact of an asteroid or some other problem would have made them go extinct at some point. 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. a. because b. so c. after d. but 9. Read the following sentence. Dinosaurs disappeared from the Earth 65 million years ago because of major changes that happened. Answer the questions below based on the information provided in the sentence you just read. One of the questions has already been answered for you. 1. What? dinosaurs 6

7 Answers: Fossils and Dinosaurs The Extinction of Dinosaurs 2. What did dinosaurs do? disappeared from the Earth 3. When? 65 million years ago 4. Why? because of major changes that happened 10. Vocabulary Word: atmosphere: the mass of air surrounding the Earth. Use the vocabulary word in a sentence: answers may vary. 7