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NGSS: ESS1.C: The history of planet Earth

CCSS: Reading Informational Text: 5

TEKS: Science: 3.2A, 4.2A, 5.2A, 6.2A; ELA: 3.16, 4.14, 5.14, 6.13

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Death of a Dinosaur

How a flood turned this dino into one of the best-preserved fossils ever found

November 2017
By Ariel Bleicher
Illustration by Gary Hanna
Jim McMahon

The day began like any other at the Millennium Mine in Alberta, Canada. Miners scraped at the side of a hill, looking for oil. But then a digging machine hit something odd. Hard brown lumps fell out of the soft earth.

A miner sent a photo to Alberta’s Royal Tyrrell Museum. Paleontologist Don Henderson visited the mine to take a look. He noticed patterns on the lumps that looked like ribs and scales. That’s when he realized what he was seeing: the fossil of a dinosaur more than 100 million years old.

That was in 2011. The miners dug out a large section of rock containing the rest of the dinosaur, called a nodosaur. Back at the museum, Henderson’s team carefully cleaned the fossil by chipping away at the rock around it. Then they put the broken pieces back together. The result is one of the most lifelike preserved dinosaurs ever found. “It looks like it died just yesterday,” says Henderson.

The day began like any other. Miners worked at the Millennium Mine in Alberta, Canada. They scraped at the side of a hill. They were looking for oil. But then a digging machine hit something odd. Hard brown lumps fell out of the soft earth.

A miner sent a photo to Alberta’s Royal Tyrrell Museum. Don Henderson visited the mine to take a look. He’s a paleontologist. Henderson saw patterns on the lumps. They looked like ribs and scales. That’s when he knew what he was seeing. It was the fossil of a dinosaur. And it was more than 100 million years old.

That was in 2011. The miners dug out a large section of rock. It held the rest of the dinosaur. It was a type called a nodosaur. Henderson took the dinosaur to the museum. His team carefully cleaned the fossil. They chipped away at the rock around it. Then they put the broken pieces back together. The result is one of the most lifelike dinosaur fossils ever found. “It looks like it died just yesterday,” says Henderson.

Fossil Finds
Watch a video about the nodosaur fossil and its new home at the Royal Tyrrell Museum.

Spiky Specimen

Nodosaurs roamed Earth beginning 150 million years ago. Back then, the area that’s now Canada was hot and wet. An ocean covered the area where the fossil was found.

The fossilized nodosaur lived on land, likely near the coast of the ocean. It was about 5.5 meters (18 feet) long and weighed more than 1,300 kilograms (2,800 pounds). Its wide body was covered in bony plates and large horns. “It was like a giant walking spiky coffee table,” says Victoria Arbour. She’s a dinosaur expert at the Royal Ontario Museum in Toronto.

Nodosaurs lived on Earth starting 150 million years ago. The area that’s now Canada was hot and wet back then. An ocean covered the area where the fossil was found.

The fossil nodosaur lived on land. It likely lived near the ocean. It was about 5.5 meters (18 feet) long. It weighed more than 1,300 kilograms (2,800 pounds). Its wide body was covered in bony plates and large horns. “It was like a giant walking spiky coffee table,” says Victoria Arbour. She’s a dinosaur expert. She works at the Royal Ontario Museum in Toronto.

Robert Clark/National Geographic Creative

Technician Mark Mitchell carefully cleans the nodosaur fossil.

Despite the nodosaur’s intimidating looks, it wasn’t a predator. It ate only plants. It used its armor to protect itself and attract mates.

Because the remains were found in an ancient seabed, scientists think the dinosaur was swept out to sea in a flood. It sank to the bottom of the ocean and was quickly buried in mud. Then the process of becoming a fossil began.

The nodosaur may have looked scary. But it wasn’t a meat-eater. It ate only plants. It used its armor to protect itself. The armor also helped it attract mates.

Scientists think the dinosaur was swept out to sea in a flood. That’s because its remains were found in an ancient seabed. The dinosaur likely sank to the bottom of the ocean. It was quickly buried in mud. Then the process of becoming a fossil began.

Buried at Sea

Robert Clark/National Geographic Creative

Scientists can learn about the nodosaur’s life by studying its remains.

Most fossils form when minerals seep into bones, slowly turning them to stone. Soft tissues, such as skin and muscles, break down. But in the nodosaur’s case, minerals hardened around its body like a shell (see Fossil Formation, below). This kept the skeleton from being crushed and protected the soft tissues from decay. Millions of years later, the dinosaur’s scaly skin and spiky armor are still intact.

Freeing the nodosaur from the ground wasn’t easy. It took workers 17 days just to carve it out with their machines. Most of the body was still encased in rock.  

Mark Mitchell, a technician at the Royal Tyrrell Museum, worked on the fossil. He had to remove the rock carefully to avoid damaging the delicate skin and bones inside. After gently chipping away each bit of rock, he would squeeze a drop of glue onto the dinosaur to hold it together. The process took him six years! In early 2017, the fossil was finally ready to be studied.

Most fossils form when minerals soak into bones. That slowly turns them to stone. The dinosaur’s skin, muscles, and other soft tissues break down. But that’s not what happened to this nodosaur. Instead, minerals hardened around its body like a shell (see Fossil Formation, below). That kept the body from being crushed. It also kept the soft tissues from decaying. The dinosaur’s scaly skin and spiky armor still remain millions of years later.

Freeing the nodosaur from the ground was hard. It took workers 17 days. That was just to carve it out with their machines. Most of the body was still surrounded by rock. 

Mark Mitchell worked on the fossil. He’s a technician. He works at the Royal Tyrrell Museum. He had to remove the rock carefully. He didn’t want to damage the delicate skin and bones inside. He would gently chip away at each bit of rock. Then he would squeeze a drop of glue onto the dinosaur. That held it together. The process took him six years! The fossil was finally ready to be studied in early 2017.

Fossil Formation

The nodosaur fossil was so well-preserved because of how it formed. Here’s what happened after the dinosaur died. 

The nodosaur fossil was so well-preserved because of how it formed. Here’s what happened after the dinosaur died. 

KATE FRANCIS

About 110 million years ago, the nodosaur was swept out to sea. Its body sank into the ocean.

About 110 million years ago, the nodosaur was swept out to sea. Its body sank into the ocean.

Minerals on the muddy seafloor quickly formed a protective shell around the body.

Minerals on the muddy seafloor quickly formed a protective shell around the body.

Over millions of years, sediment piled up and hardened into rock. The ocean above it dried up.

Over millions of years, sediment piled up and hardened into rock. The ocean above it dried up.

In 2011, miners were digging a large pit in the area. They cut into a rock and found the fossil.

In 2011, miners were digging a large pit in the area. They cut into a rock and found the fossil.

Think: Why might well-preserved fossils be so rare?

Think: Why might well-preserved fossils be so rare?

Fossil Formation

The nodosaur fossil was so well-preserved because of how it formed. Here’s what happened after the dinosaur died. 

The nodosaur fossil was so well-preserved because of how it formed. Here’s what happened after the dinosaur died. 

KATE FRANCIS

About 110 million years ago, the nodosaur was swept out to sea. Its body sank into the ocean.

About 110 million years ago, the nodosaur was swept out to sea. Its body sank into the ocean.

Minerals on the muddy seafloor quickly formed a protective shell around the body.

Minerals on the muddy seafloor quickly formed a protective shell around the body.

Over millions of years, sediment piled up and hardened into rock. The ocean above it dried up.

Over millions of years, sediment piled up and hardened into rock. The ocean above it dried up.

In 2011, miners were digging a large pit in the area. They cut into a rock and found the fossil.

In 2011, miners were digging a large pit in the area. They cut into a rock and found the fossil.

Think: Why might well-preserved fossils be so rare?

Think: Why might well-preserved fossils be so rare?

Dinosaur Secrets

When Henderson’s team compared the fossil with other nodosaurs, they realized it was a species they’d never seen before. They decided to name it in honor of Mitchell. They called it Borealopelta markmitchelli (BOR-ee-uhl-oh-pel-tuh mark-mih-CHEL-ee).

Because the fossil is so well-preserved, scientists can learn a lot about the nodosaur’s life. For example, pebble-sized masses in its stomach may be from its last meal. Henderson hopes to analyze them to find out what the dinosaur ate.

Henderson’s team compared the fossil with those of other nodosaurs. They realized it was a new species. It was one they’d never seen before. They decided to name it in honor of Mitchell. They called it Borealopelta markmitchelli (BOR-ee-uhl-oh-pel-tuh mark-mih-CHEL-ee).

The fossil is very well preserved. It’s helping scientists learn a lot about the nodosaur’s life. For example, the dinosaur had pebble-sized masses in its stomach. They may be from its last meal. Henderson hopes to study them. Then he can find out what the dinosaur ate.

Robert Clark/National Geographic Creative

The dinosaur’s spiky armor was perfectly preserved when it became a fossil.

The dinosaur’s skin also contains traces of chemicals that indicate its color. By examining the skin under a microscope, scientists can tell how it used to look. When the nodosaur was alive, they found, its skin was reddish brown.

The remarkable fossil is now on display at the Royal Tyrrell Museum. Henderson hopes many people visit it. “Maybe somebody will come along who sees something new,” he says.

The dinosaur’s skin also contains traces of chemicals. They can reveal the skin’s color. Scientists examined the skin under a microscope. They learned how it used to look. The nodosaur’s skin was reddish-brown when it was alive.

The amazing fossil is now on display at the Royal Tyrrell Museum. Henderson hopes many people visit it. “Maybe somebody will come along who sees something new,” he says.

Dino Dig

Can you extract and clean a fossil without damaging it?

Step 3

Observe

When the nodosaur fossil was found, it was completely encased in rock. A technician had to carefully remove and clean it before it could be studied.  

When the nodosaur fossil was found, it was completely encased in rock. A technician had to carefully remove and clean it before it could be studied.  

Define the Problem

Can you design a method for extracting and cleaning a fossil without harming it?

Can you design a method for extracting and cleaning a fossil without harming it?

Materials

• newspaper or butcher paper
• two cereal treats with “fossils” inside (Teachers: See page T6 in this issue’s Teacher’s Guide for preparation instructions.)
• plastic spoon
• other excavation tools, such as toothpicks, paper clips, and brushes
• pencil and paper

• newspaper or butcher paper
• two cereal treats with “fossils” inside (Teachers: See page T6 in this issue’s Teacher’s Guide for preparation instructions.)
• plastic spoon
• other excavation tools, such as toothpicks, paper clips, and brushes
• pencil and paper

Design a Solution

1. Work with a partner. Cover your desk or table with paper. This could get messy! 

2. Get a cereal treat from your teacher. This is your rock with a fossil inside. Place the rock on the paper and draw a circle around it. Make sure you don’t move the treat outside the circle during this activity.

3. While one partner holds the rock in place, the other partner should dig into it with the spoon. Keep digging until you find the fossil. Using only the spoon, remove the fossil from the rock. Record what animal it is.

4. Are any bits of rock still stuck to the fossil? Try to clean them off using only the spoon. Then inspect your fossil. Is there any damage? Record your observations.

5. Could you do a better job extracting and cleaning another fossil? Work with your partner to plan a new method using the tools available to you. Write down your plan. Then get a new rock from your teacher and repeat steps 2 through 4.

1. Work with a partner. Cover your desk or table with paper. This could get messy! 

2. Get a cereal treat from your teacher. This is your rock with a fossil inside. Place the rock on the paper and draw a circle around it. Make sure you don’t move the treat outside the circle during this activity.

3. While one partner holds the rock in place, the other partner should dig into it with the spoon. Keep digging until you find the fossil. Using only the spoon, remove the fossil from the rock. Record what animal it is.

4. Are any bits of rock still stuck to the fossil? Try to clean them off using only the spoon. Then inspect your fossil. Is there any damage? Record your observations.

5. Could you do a better job extracting and cleaning another fossil? Work with your partner to plan a new method using the tools available to you. Write down your plan. Then get a new rock from your teacher and repeat steps 2 through 4.

Conclusions

1. What tools did you use to extract your second fossil? Why did you choose those tools? 

2. How did the second fossil dig compare with the first one? Was your new method an improvement? 

3. Imagine you’re in charge of digging up and cleaning the nodosaur fossil. Based on this activity, what tools do you think you would need?

1. What tools did you use to extract your second fossil? Why did you choose those tools? 

2. How did the second fossil dig compare with the first one? Was your new method an improvement? 

3. Imagine you’re in charge of digging up and cleaning the nodosaur fossil. Based on this activity, what tools do you think you would need?

Dino Dig

Can you extract and clean a fossil without damaging it?

Step 3

Observe

When the nodosaur fossil was found, it was completely encased in rock. A technician had to carefully remove and clean it before it could be studied.  

When the nodosaur fossil was found, it was completely encased in rock. A technician had to carefully remove and clean it before it could be studied.  

Define the Problem

Can you design a method for extracting and cleaning a fossil without harming it?

Can you design a method for extracting and cleaning a fossil without harming it?

Materials

• newspaper or butcher paper
• two cereal treats with “fossils” inside (Teachers: See page T6 in this issue’s Teacher’s Guide for preparation instructions.)
• plastic spoon
• other excavation tools, such as toothpicks, paper clips, and brushes
• pencil and paper

• newspaper or butcher paper
• two cereal treats with “fossils” inside (Teachers: See page T6 in this issue’s Teacher’s Guide for preparation instructions.)
• plastic spoon
• other excavation tools, such as toothpicks, paper clips, and brushes
• pencil and paper

Design a Solution

1. Work with a partner. Cover your desk or table with paper. This could get messy! 

2. Get a cereal treat from your teacher. This is your rock with a fossil inside. Place the rock on the paper and draw a circle around it. Make sure you don’t move the treat outside the circle during this activity.

3. While one partner holds the rock in place, the other partner should dig into it with the spoon. Keep digging until you find the fossil. Using only the spoon, remove the fossil from the rock. Record what animal it is.

4. Are any bits of rock still stuck to the fossil? Try to clean them off using only the spoon. Then inspect your fossil. Is there any damage? Record your observations.

5. Could you do a better job extracting and cleaning another fossil? Work with your partner to plan a new method using the tools available to you. Write down your plan. Then get a new rock from your teacher and repeat steps 2 through 4.

1. Work with a partner. Cover your desk or table with paper. This could get messy! 

2. Get a cereal treat from your teacher. This is your rock with a fossil inside. Place the rock on the paper and draw a circle around it. Make sure you don’t move the treat outside the circle during this activity.

3. While one partner holds the rock in place, the other partner should dig into it with the spoon. Keep digging until you find the fossil. Using only the spoon, remove the fossil from the rock. Record what animal it is.

4. Are any bits of rock still stuck to the fossil? Try to clean them off using only the spoon. Then inspect your fossil. Is there any damage? Record your observations.

5. Could you do a better job extracting and cleaning another fossil? Work with your partner to plan a new method using the tools available to you. Write down your plan. Then get a new rock from your teacher and repeat steps 2 through 4.

Conclusions

1. What tools did you use to extract your second fossil? Why did you choose those tools? 

2. How did the second fossil dig compare with the first one? Was your new method an improvement? 

3. Imagine you’re in charge of digging up and cleaning the nodosaur fossil. Based on this activity, what tools do you think you would need?

1. What tools did you use to extract your second fossil? Why did you choose those tools? 

2. How did the second fossil dig compare with the first one? Was your new method an improvement? 

3. Imagine you’re in charge of digging up and cleaning the nodosaur fossil. Based on this activity, what tools do you think you would need?

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