Illustrations by Shane Rebenschied

Last Days of the Dinosaurs

Dinosaurs ruled the planet for more than 150 million years—until a single disastrous event changed everything.

By Alessandra Potenza

From the December 2024/January 2025 Issue

Learning Objective: to identify key ideas and details in a narrative nonfiction article

Lexiles: 920L, 750L

Featured Skill: Key Ideas and Details,

Other Key Skills: supporting details, cause and effect, critical thinking

Listen to this story read aloud.

AS YOU READ

How did Walter Alvarez change our understanding of Earth’s history?

It was 66 million years ago in western North America. And the world was about to change forever.

As the sun rose, the loud buzzing of bloodsucking flies filled the muggy air. A warm mist hung over the thick forests. Prowling through the jungle in search of prey was a huge monster covered in dark scales and scraggly fuzz. This was the most fearsome of all the dinosaurs: Tyrannosaurus rex (or T. rex).

Sniffing the air, the creature let out a deep growl. Its enormous mouth flashed more than 50 razor-sharp teeth, each fang about 8 inches long.

Then, disaster struck.

All of a sudden, the ground beneath the T. rex began to shake so powerfully it seemed as if it might actually be crumbling. Burning rocks rained down from the sky. The air grew so hot that trees everywhere burst into flames.

By the time the destruction had quieted down, the landscape was in ruins. The T. rex—the fiercest predator on land—was dead, along with countless other creatures.

Life on Earth would never be the same.

It was 66 million years ago in western North America. And the world was about to change forever.

As the sun rose, the buzzing of bloodsucking flies filled the air. A warm mist hung over the thick forests. A huge creature was searching for prey. The creature was covered in dark scales and scraggly fuzz. This creature was the most fearsome of all the dinosaurs: Tyrannosaurus rex (or T. rex).

The creature growled. It flashed more than 50 razor-sharp teeth. Each fang was about 8 inches long.

Then, disaster struck.

Suddenly, the ground beneath the T. rex began to shake. Burning rocks fell from the sky. The air grew very hot. Trees burst into flames.

Finally, the destruction quieted down. But the landscape was in ruins. And the T. rex—the fiercest predator on land—was dead, along with countless other creatures.

Life on Earth would never be the same.

The Age of the Dinosaurs

Shutterstock.com (T. rex fossil)

Before this disaster shook the planet, dinosaurs had walked the earth for more than 150 million years, during a period known as the Mesozoic Era. (This time period is also referred to as the age of the dinosaurs.)

The first dinosaurs were not the giant, nightmarish beasts we’re used to seeing in movies. Dinosaurs started out small and lightweight, “only about the size of dogs,” according to Steve Brusatte, a paleontologist at the University of Edinburgh in Scotland. (A paleontologist is a scientist who studies ancient animals and plants.)

By 66 million years ago, however, dinosaurs had grown much larger. If you’d been around back then, you would have stared in awe at a group of Alamosauruses (a-la-moh-SOR-uhs-es) stretching their long necks to munch on the leaves of tall trees. These prehistoric giants likely weighed at least 33 tons—as much as a fully loaded cement truck. You would have felt the ground rumble as a herd of Triceratops (trahy-SEHR-uh-tahps) lumbered by. These tanklike creatures had three sharp horns: one above each eye and another on their beaky nose.

And of course, you would have cowered if you had come across the king of all dinosaurs, the largest meat-eating animal ever to stalk the land, T. rex. About the size and weight of a school bus, it used its short, strong arms and knifelike claws to pin down its victims and pierce their scaly flesh. Its powerful jaws could crack through bone in a single bite.

For millennia, T. rex and other dinosaurs ruled the land, gobbling up all types of flora and fauna, from lacy ferns and spiny palms to scurrying mammals and slithering snakes. That is, until about 66 million years ago—when the dinosaurs seemingly vanished.

Before this disaster, dinosaurs had walked the earth for more than 150 million years. That time period is called the Mesozoic Era. (It is also called the age of the dinosaurs.)

The first dinosaurs were not huge and scary, like we see in the movies. Dinosaurs started out small. They were “only about the size of dogs,” according to Steve Brusatte. He’s a paleontologist at the University of Edinburgh in Scotland. (A paleontologist is a scientist who studies ancient animals and plants.)

By 66 million years ago, however, dinosaurs had grown much larger. Imagine you lived back then. You would have stared in awe as a group of Alamosauruses (a-la-moh-SOR-uhs-es) stretched their long necks to eat the leaves of tall trees. These giants likely weighed at least 33 tons. That’s as much as a fully loaded cement truck. You would have felt the ground rumble as a herd of Triceratops (trahy-SEHR-uh-tahps) lumbered by. These tanklike creatures had three sharp horns: one above each eye and another on their beaky nose.

And of course, you would have trembled in fear if you came across the T. rex, the king of all dinosaurs. It was the largest meat-eating animal ever to stalk the land. It was about the size and weight of a school bus. It used its short, strong arms and knifelike claws to pin down its victims and pierce their scaly flesh. Its powerful jaws could crack through bone in a single bite.

T. rex and other dinosaurs ruled the land. They ate all types of flora and fauna, from lacy ferns and spiny palms to scurrying mammals and slithering snakes. But then, about 66 million years ago, dinosaurs vanished.

An Ancient Mystery

For a long time, the reason dinosaurs disappeared remained one of the world’s greatest mysteries. Even experts didn’t know for sure. Then in the 1970s, an American scientist named Walter Alvarez made a discovery that would eventually provide an answer.

As a researcher, Alvarez’s area of study wasn’t dinosaurs. He was a geologist—his specialty was rocks. The layers of rock beneath our feet are like a thick history book telling the story of our planet. Rocks get older as you move deeper underground, each layer a different chapter in Earth’s past. Some contain fossils of long-gone animals and plants. Others hold clues to ancient landscapes and climates.

By analyzing rocks, scientists had determined that something happened about 66 million years ago. When they studied the layers of rock from before that time, they saw dinosaur fossils everywhere: bones, claws, teeth, and eggs. Even petrified dino poop. But such fossils were absent from the layers of rock that had formed after that time. What had happened?

Clearly, dinosaurs had become extinct. But how and why? Some scientists thought that dinosaurs had died out because the planet’s climate had gradually changed, becoming too cold. Or perhaps it had grown too hot. Or maybe dinosaurs had simply grown too big and slow for their own good, and as a result, struggled to survive.

Whatever happened, most scientists assumed it had happened over millions of years. Up until the 1970s, it was believed that no single disaster could rapidly annihilate millions of species all around the planet.

But what if it could?

One of the first people to ask that question was Walter Alvarez.

For a long time, the reason dinosaurs disappeared remained a mystery. Even experts didn’t know for sure. Then in the 1970s, an American scientist named Walter Alvarez made a discovery. It would eventually provide an answer.

Alvarez was a geologist. His specialty was rocks, not dinosaurs. The layers of rock beneath our feet are like a history book. They tell the story of our planet. Rocks get older as you move deeper underground. Each layer is a different chapter in Earth’s past. Some contain fossils of long-gone animals and plants. Others hold clues to ancient landscapes and climates.

By analyzing rocks, scientists had determined that something happened about 66 million years ago. The layers of rock from before that time had dinosaur fossils everywhere: bones, claws, teeth, and eggs. Even petrified dino poop. But such fossils were absent from the layers of rock that formed after that time. What had happened?

Clearly, dinosaurs had become extinct. But how and why? Some scientists thought that dinosaurs had died out because the planet’s climate had changed, becoming too cold. Or perhaps it had grown too hot. Or maybe dinosaurs had grown too big and slow and struggled to survive.

Most scientists assumed that dinosaurs had died off over millions of years. Up until the 1970s, it was believed that a single disaster could not quickly annihilate millions of species all around the planet.

But what if it could?

One of the first people to ask that question was Walter Alvarez.

A Surprise Discovery

Alvarez’s obsession with dinosaurs—and the mystery of their disappearance—began during a research trip in Italy in the 1970s. While working in a gorge, he noticed (as other scientists had before him) a 1-centimeter layer of dark, soft clay cutting through the cliff walls. This layer of clay was sandwiched between rock rich with fossils from the time of the dinosaurs and the rock layers with very few fossils from the period after dinosaurs disappeared.

What was that thin layer of dark clay in the cliff? If rocks were like a history book, this layer of clay felt to Alvarez like an important page. But he had no idea how to read it.

So he called his father, Luis, for help. Luis Alvarez was also a scientist, and he was known for thinking outside the box. He suggested testing the clay to learn more about what it was made of and how it had formed.

What the men discovered came as a complete surprise: The clay was full of a metal, iridium (ih-RIH-dee-uhm). This particular metal is very rare on Earth’s surface—but a lot of it can be found in space. What could possibly explain all that iridium in the clay?

Alvarez soon found that the presence of the metal wasn’t unique to Italy. In 1978, he traveled to the northern European country of Denmark to do additional research. There he found iridium-rich clay dating to the exact same time as the clay in Italy.

Alvarez’s obsession with the disappearance of dinosaurs began during a research trip in the 1970s. He was in Italy working in a gorge. He noticed (as other scientists had before him) a 1-centimeter layer of clay. This layer of clay was sandwiched between two layers of rock. One layer, from the Mesozoic Era, was rich with dinosaur fossils. The other layer, from the period after dinosaurs disappeared, had no dinosaur fossils.

What was that thin layer of clay between them? If rocks were like a history book, this layer of clay felt to Alvarez like an important page. But he had no idea how to read it.

So he called his father, Luis, for help. Luis Alvarez was also a scientist. He suggested testing the clay to learn more about it.

What the men discovered came as a surprise: The clay was full of a metal called iridium (ih-RIH-dee-uhm). This type of metal is rare on Earth’s surface. But a lot of it can be found in space. How did iridium get in the clay?

Alvarez soon found that Italy was not the only place with iridium-rich clay. In 1978, he traveled to the European country of Denmark. There he found iridium-rich clay dating to the exact same time as the clay in Italy.

A Shocking Theory

Alvarez spent many sleepless nights tossing and turning, thinking about all the possible explanations for this phenomenon. But only one made sense. If iridium is mostly found in space, the metal must have come from there. Maybe an asteroid—a giant space rock—had slammed into Earth, spraying iridium all over the planet.

And maybe that asteroid was also to blame for the dinosaurs’ extinction.

In 1980, Alvarez published his and his father’s research in the scientific journal Science. Almost immediately, their paper whipped up a storm of confusion and disbelief among members of the scientific community.

Alvarez and his father were challenging what experts had believed for decades: that all changes on the planet happen gradually, with different plant and animal species appearing and dying out over the course of millions of years.

“Alvarez’s theory was a big deal,” says Brusatte. “At first, it was controversial. Most scientists did not accept it.”

But by the late 1980s, more findings from researchers around the globe seemed to confirm the asteroid theory. High levels of iridium were discovered all over the world in layers of clay and other sediments from the time of the extinction. Many of those layers also contained tiny balls of glass that are usually formed by the intense heat of an asteroid crash.

As the years passed and the evidence grew, more and more scientists started to agree with Alvarez.

Alvarez spent many sleepless nights thinking about all the possible explanations for this phenomenon. But only one made sense. Iridium is mostly found in space. Therefore, the metal must have come from there. Maybe an asteroid—a giant space rock—had slammed into Earth, spraying iridium all over the planet.

And maybe that asteroid was also to blame for the dinosaurs’ extinction.

In 1980, Alvarez published his and his father’s research in the scientific journal Science. The scientific community reacted to their paper with confusion and disbelief.

“Alvarez’s theory was a big deal,” says Brusatte. “At first, it was controversial. Most scientists did not accept it.”

But by the late 1980s, more findings from other researchers seemed to confirm the asteroid theory. High levels of iridium were discovered all over the world in layers of clay and other sediments from the time of the extinction. Many of those layers also contained tiny balls of glass that are usually formed by the heat of an asteroid crash.

The years passed and the evidence grew. More scientists started to agree with Alvarez.

A Cold, Dark World

Charles Brutlag/Alamy Stock Photo (bird)

Yes, birds are dinosaurs! They descend from the only dinosaurs that survived the asteroid’s aftermath.

Then in 1991, the most convincing clue of all was revealed: an enormous crater off the coast of Mexico, dating to 66 million years ago. Mostly buried under the sea, the crater is an estimated 120 miles across and 12 miles deep. Only one thing could have made a hole that big in the ground—an absolutely enormous asteroid.

“It was a bombshell,” Alvarez later wrote.

The crater helped to finally confirm Alvarez’s theory. It also allowed Alvarez and other scientists to figure out just how massive the asteroid was—up to 9 miles in diameter.

The gargantuan asteroid instantly destroyed everything within 600 miles of where it hit. But that was just the beginning. Within minutes, the crash triggered earthquakes more powerful than those ever felt by humans. Waves three times as high as the Empire State Building slammed into coasts. Wildfires broke out, the flames engulfing the land.

The destruction didn’t end there.

Ash from the fires and massive clouds of dust from the asteroid’s impact soon covered the planet like a blanket, blocking sunlight. For the next 15 years, the globe was shrouded in darkness. In this cold, dark world, plants couldn’t grow. Any animals that had survived the immediate aftermath of the asteroid crash were now caught in a deadly chain reaction. Without plants, herbivores—or plant eaters—starved to death. Carnivores, or meat eaters, came next.

Scientists estimate that three out of every four species on Earth eventually died out as a result of the asteroid strike. This includes all dinosaurs—long-necked, sharp-toothed, duck-billed, and more—except for a small number of avian dinosaurs, or birds. Just like that, the age of the dinosaurs was over.

Then in 1991, the most convincing clue of all was revealed. An enormous crater was found off the coast of Mexico. It dated to 66 million years ago. Mostly buried under the sea,

the crater is an estimated 120 miles across and 12 miles deep. Only one thing could have made a hole that big in the ground—an absolutely enormous asteroid.

“It was a bombshell,” Alvarez later wrote.

The crater helped confirm Alvarez’s theory. It also allowed Alvarez and other scientists to figure out just how massive the asteroid was—up to 9 miles in diameter.

The gigantic asteroid instantly destroyed everything within 600 miles of where it hit. Then, within minutes, the crash triggered earthquakes more powerful than those ever felt by humans. Waves three times as high as the Empire State Building slammed into coasts. Wildfires broke out. The flames engulfed the land.

The destruction didn’t end there.

Ash from the fires and clouds of dust from the asteroid’s impact soon covered the planet like a blanket, blocking sunlight. For the next 15 years, the globe was shrouded in darkness. In this cold, dark world, plants couldn’t grow. Animals that had survived the asteroid crash were now caught in a deadly chain reaction. Without plants, herbivores—or plant eaters—starved to death. Carnivores, or meat eaters, came next.

Scientists estimate that three out of every four species on Earth eventually died out as a result of the asteroid strike. This includes all dinosaurs except for a small number of avian dinosaurs, or birds. Just like that, the age of the dinosaurs was over.

Survivors

Yet slowly, the planet recovered. As the darkness lifted, shafts of sunlight began streaming across the scarred land. Seeds started to sprout and grow into thick forests.

In this new world, there was no T. rex crashing through the trees. But there were other, luckier species that had managed to survive: cockroaches, frogs, crocodiles, snakes, fish, and birds that had found shelter underground or deep in caves and ponds. Some small mammals survived too.

And after the dinosaurs were wiped out, those mammals thrived. Over millions of years, mammals grew in size. They spread far and wide as countless new types evolved—rats, sloths, whales . . . and eventually, humans.

As strange as it might seem, it’s likely that we wouldn’t be here if it weren’t for that disastrous day 66 million years ago.

Yet slowly, the planet recovered. The darkness lifted. Shafts of sunlight began streaming across the scarred land. Seeds started to sprout. Forests grew.

In this new world, there was no T. rex. But there were other, luckier species that had managed to survive: cockroaches, frogs, crocodiles, snakes, fish, and birds that had found shelter underground or deep in caves and ponds. Some small mammals survived too.

And after the dinosaurs were wiped out, those mammals thrived. Over millions of years, mammals grew in size. Countless new types evolved—rats, sloths, whales . . . and eventually, humans.

As strange as it might seem, we might not be here if it weren’t for that disastrous day 66 million years ago.

Writing Prompt

Write a series of journal entries from Walter Alvarez’s point of view: one when Alvarez was in Italy, one after the publication of his research, and one after he learned about the asteroid crater.

Writing Prompt

Write a series of journal entries from Walter Alvarez’s point of view: one when Alvarez was in Italy, one after the publication of his research, and one after he learned about the asteroid crater.

^{This article was originally published in the December 2024/January 2025 issue.}

video (1)

Audio ()

Activities (9)

Quizzes (1)

Answer Key (1)

video (1)

Audio ()

Activities (9)

Quizzes (1)

Answer Key (1)

Essential Questions: What do we gain by learning about Earth’s history? How do you prove a theory? What makes an idea controversial?

1. Prepare to Read

(10 minutes)

Preview Vocabulary (10 minutes)

Project the Google Slides version of Vocabulary: Definitions and Practice on your whiteboard. Review the definitions and complete the activity as a class. Highlighted words: annihilate, controversial, gorge, lumbered, petrified, phenomenon. Audio pronunciations of the words and a read-aloud of the definitions are embedded on the slides. Optionally, print the PDF version or share the slideshow link directly to your LMS and have students preview the words and complete the activity independently before class.

Watch a Video (15 minutes)

Watch the Beyond the Story video, in which author Alessandra Potenza provides background about the age of the dinosaurs. Have students respond to the Video Discussion Questions (available in your Resources tab) in pairs or small groups.

2. Read and Discuss

(45 minutes)

Invite a volunteer to read the As You Read box on page 4 or at the top of the digital story page.

Read the article once as a class. (Differentiation: Share the lower-Lexile version or the Spanish version of the article.) Optionally, have students listen to author Alessandra Potenza read the article aloud while they follow along. The audio read-aloud is located in the Resources tab in Teacher View and at the top of the story page in Student View.

Divide students into groups to read the article again and respond to the following Discussion Questions, also located in the Resources tab.

Invite a volunteer to read the As You Read box on page 4 or at the top of the digital story page.

Read the article once as a class. (Differentiation: Share the lower-Lexile version or the Spanish version of the article.) Optionally, have students listen to author Alessandra Potenza read the article aloud while they follow along. The audio read-aloud is located in the Resources tab in Teacher View and at the top of the story page in Student View.

Divide students into groups to read the article again and respond to the following Discussion Questions, also located in the Resources tab.

Discussion Questions (30 minutes)

1. In the introduction, author Alessandra Potenza describes the T. rex as “the fiercest predator on land.” Which details throughout the article support this description? (supporting details) The author describes the T. rex as a “huge monster” that was “prowling through the jungle in search of prey.” She says it was the most fearsome of all the dinosaurs and describes its “deep growl” and “enormous mouth” that had more than “50 razor-sharp teeth, each fang about 8 inches long.” In the section “The Age of the Dinosaurs,” Potenza mentions that readers would have “cowered” in front of the T. rex, which was about the size and weight of a school bus. Additionally, she states, “it used its short, strong arms and knifelike claws to pin down its victims and pierce their scaly flesh. Its powerful jaws could crack through bone in a single bite.” These details support the idea that the T. rex was a fierce predator.

2. Before Walter Alvarez’s discovery, what did people believe happened to the dinosaurs? (key ideas and details) Before Walter Alvarez’s discovery, there were several theories about what happened to the dinosaurs. Some scientists thought dinosaurs died out because the planet’s climate had gradually changed, becoming too hot or too cold. Others thought dinosaurs had grown too big and slow, and as a result, struggled to survive. Most scientists agreed that whatever had happened to the dinosaurs, it happened over millions of years.

3. How did Alvarez solve the mystery of the dinosaurs’ disappearance? (key ideas and details) During a research trip to Italy, Alvarez began to question a 1-centimeter layer of dark, soft clay cutting through a cliff wall. He and his father worked together to test the clay to learn what it was made from and how it formed. They learned that the clay was full of a metal called iridium that is mostly found in space. Then, during a research trip in Denmark, he discovered more iridium-rich clay dating to the exact same time as the clay in Italy. He began to suspect that the metal must have come from an enormous asteroid that had slammed into Earth, causing the extinction of dinosaurs. Finally, in 1991, a huge crater off the coast of Mexico was discovered. The crater dated back to the same time as the clay, confirming Alvarez’s theory.

4. What were the effects of the asteroid that hit Earth? (cause and effect) When the gargantuan asteroid slammed into Earth, it instantly destroyed everything within 600 miles of where it hit. It also triggered powerful earthquakes, massive waves, and wildfires that engulfed Earth. Ash from the fires and massive clouds of dust from the asteroid’s impact covered the planet, leaving Earth a cold, dark world for the next 15 years. Most of the surviving plants and animals eventually died out.

5. What conclusions can be drawn about the extinction of the dinosaurs and recovery of Earth? (critical thinking) Answers will vary. Students may offer that even the fiercest species are not invincible. Survival can be extremely difficult and life can change in an instant. The planet is resilient and can recover from extreme disasters. It also tells us that the planet is made up of survivors.

2. Before Walter Alvarez’s discovery, what did people believe happened to the dinosaurs? (key ideas and details) Before Walter Alvarez’s discovery, there were several theories about what happened to the dinosaurs. Some scientists thought dinosaurs died out because the planet’s climate had gradually changed, becoming too hot or too cold. Others thought dinosaurs had grown too big and slow, and as a result, struggled to survive. Most scientists agreed that whatever had happened to the dinosaurs, it happened over millions of years.

3. Write About It: Key Ideas and Details

(45 minutes)

Have students complete the Featured Skill Activity: Key Ideas and Details. This activity prepares them to respond to the writing prompt on page 8 in the printed magazine and at the bottom of the digital story page:

Write a series of journal entries from Walter Alvarez’s point of view: one when Alvarez was in Italy, one after the publication of his research, and one after he learned about the asteroid crater.

Alternatively, have students choose a task from the Choice Board, a menu of culminating tasks. (Our Choice Board options include the writing prompt from the magazine, differentiated versions of the writing prompt, and additional creative ways for students to demonstrate their understanding of a story or article.)

Support for Multilingual Learners

These questions are designed to help students respond
to the text at a level that’s right for them.

Yes/No Questions

Ask students to demonstrate comprehension with a very simple answer.

1. Is the T. rex extinct? Yes, it is.

2. Did a slow change in the weather kill the dinosaurs? No, it didn’t.

3. Did Walter Alvarez study rocks? Yes, he did.

4. Did people believe Alvarez’s theory at first? No, they didn’t.

5. Did a huge hole in the ground help prove Alvarez’s theory? Yes, it did.

Ask students to demonstrate comprehension with a very simple answer.

1. Is the T. rex extinct? Yes, it is.

2. Did a slow change in the weather kill the dinosaurs? No, it didn’t.

3. Did Walter Alvarez study rocks? Yes, he did.

4. Did people believe Alvarez’s theory at first? No, they didn’t.

5. Did a huge hole in the ground help prove Alvarez’s theory? Yes, it did.

Either/Or Questions

Encourage students to use language from the question in their answer.

1. Did the dinosaurs go extinct slowly over time or quickly because of an asteroid? Dinosaurs went extinct quickly because of an asteroid.

2. Is the metal iridium usually found on Earth or in space? Iridium is usually found in space.

3. Did Alvarez find metal only in Italy or in other places too? Alvarez found metal in other places too.

4. Was a huge crater discovered in Italy or Mexico? The crater was discovered in Mexico.

5. Did Alvarez’s theory cause or clear up confusion at first? Alvarez’s theory caused confusion at first.

Encourage students to use language from the question in their answer.

1. Did the dinosaurs go extinct slowly over time or quickly because of an asteroid? Dinosaurs went extinct quickly because of an asteroid.

2. Is the metal iridium usually found on Earth or in space? Iridium is usually found in space.

3. Did Alvarez find metal only in Italy or in other places too? Alvarez found metal in other places too.

4. Was a huge crater discovered in Italy or Mexico? The crater was discovered in Mexico.

5. Did Alvarez’s theory cause or clear up confusion at first? Alvarez’s theory caused confusion at first.

Short-Answer Questions

Challenge students to produce simple answers on their own.

1. Why is it helpful to study rocks? Some rocks have fossils in them, which can tell us about the history of Earth.

2. What mystery did Walter Alvarez solve? Alvarez solved the mystery of how the dinosaurs died out.

Challenge students to produce simple answers on their own.

1. Why is it helpful to study rocks? Some rocks have fossils in them, which can tell us about the history of Earth.

2. What mystery did Walter Alvarez solve? Alvarez solved the mystery of how the dinosaurs died out.

Language Acquisition Springboard:

Fill in the five “W” words while reading, then use the answers to generate questions after reading.

Who? (Which person or people is this article mainly about?) Walter Alvarez

What? (What action or event does this article describe?) Alvarez’s research about an asteroid that hit Earth

When? (At what time did this event occur?) 66 million years ago and 1970s-1990s

Where? (In what place or location did this event take place?) Planet Earth (specifically Italy, Denmark, Mexico)

Why? (What was the cause of this event?) Alvarez's research led to learning about an asteroid that hit Earth and caused the dinosaurs to die out.

Fill in the five “W” words while reading, then use the answers to generate questions after reading.

Who? (Which person or people is this article mainly about?) Walter Alvarez

What? (What action or event does this article describe?) Alvarez’s research about an asteroid that hit Earth

When? (At what time did this event occur?) 66 million years ago and 1970s-1990s

Where? (In what place or location did this event take place?) Planet Earth (specifically Italy, Denmark, Mexico)

Why? (What was the cause of this event?) Alvarez's research led to learning about an asteroid that hit Earth and caused the dinosaurs to die out.

Connected readings from the Scope archives

Stories about discovery and the age of the dinosaurs:

Narrative Nonfiction: “The Bone Hunter”
Drama: “The Space Rock”

Stories about discovery and the age of the dinosaurs:

Narrative Nonfiction: “The Bone Hunter”
Drama: “The Space Rock”

Text-to-Speech

Last Days of the Dinosaurs

Close Reading, Critical Thinking, Skill Building

1. Prepare to Read

(10 minutes)

Preview Vocabulary (10 minutes)

Watch a Video (15 minutes)

2. Read and Discuss

(45 minutes)

Discussion Questions (30 minutes)

3. Write About It: Key Ideas and Details

(45 minutes)

Support for Multilingual Learners

These questions are designed to help students respond
to the text at a level that’s right for them.

Yes/No Questions

Either/Or Questions

Short-Answer Questions

Language Acquisition Springboard:

Connected readings from the Scope archives

Help/Support

Help/Support

About Us

Subscriber Information

Last Days of the Dinosaurs

Close Reading, Critical Thinking, Skill Building

1. Prepare to Read

(10 minutes)

Preview Vocabulary (10 minutes)

Watch a Video (15 minutes)

2. Read and Discuss

(45 minutes)

Discussion Questions (30 minutes)

3. Write About It: Key Ideas and Details

(45 minutes)

Support for Multilingual Learners

These questions are designed to help students respond to the text at a level that’s right for them.

Yes/No Questions

Either/Or Questions

Short-Answer Questions

Language Acquisition Springboard:

Connected readings from the Scope archives

Help/Support

Help/Support

About Us

Subscriber Information

Connect with Us

These questions are designed to help students respond
to the text at a level that’s right for them.