Topiz Lesson

Topic 7 Lesson 3-Fossils

OBEJECTIVE

WE CAN Use fossil data to argue how some living things have responded to climate changes.

VOCABULARY

ARGUE: TO MAKE CLAIMS SUPPORTED BY EVIDENCE

SPORTS CONNECTION

Hockey and snowboarding are sports that people enjoy in the ice and snow. Baseball is not. In the past, most sports were played outside. Hockey took place in winter on frozen ponds. Golfers played on the green spring grass. People played baseball on warm, dry summer days.

SPORTS CONNECTION

Today, technology has changed how seasons affect sports. Indoor arenas make ice-skating possible all year. Machines make snow for skiers when winter weather does not. Even football has moved to indoor stadiums to avoid unpleasant weather. Even so, not all sports can avoid the weather. Baseball players in outdoor stadiums still stop playing when rain falls heavily.

CHANGES OVER TIME

From fossil clues, scientists know that the environments of a particular area have changed a lot over time. More than 250 million years ago, the Mojave Desert was covered by a shallow sea. Some of the organisms that lived there were very different from the organisms that live there today.

CHANGES OVER TIME

Then, between 225 and 65 million years ago, the seas dried up. The climate became dry and windy. Most organisms that had lived in the sea environment could not live in such a dry place. Desert plants, such as cacti and yucca, grew. Plants provided food for animals.

EVIDENCE OF CLIMATE CHANGE

Climate on Earth has a pattern of warming and cooling. Scientists know that climate changes because they have fossil evidence. Different kinds of organisms need different climate conditions to survive. Some kinds of organisms cannot survive when even a small climate change happens.

EVIDENCE OF CLIMATE CHANGE

Fossils of plant seeds give scientists good evidence for climate change. Different kinds of plants survive in different climates. If a seed of a particular kind of plant is found in a rock layer, scientists can infer what the climate was like when the plant was living.

CLIMATE CHANGE AND EXTINCTION

Scientists argue, or make claims supported by evidence. They use fossil evidence to argue that climate change can cause extinction. After big climate changes, some organisms no longer appear in the later fossil record. The kinds of organisms that could not live in the changed environment became extinct.

CLIMATE CHANGE AND EXTINCTION

Scientists found this fossil of an extinct crocodile in a desert in Wyoming. In ancient times, a huge lake covered the area.

TIME TO TEST YOUR KNOWLEDGE

Multiple Choice

Which statement shows fossil evidence that a climate change took place in the location where the fossil was found?

• A fossil of a crocodile is found in a swamp.

• A fossil of a whale is found on a mountaintop.

• A fossil of a shelled animal is found in a riverbed.

• A fossil of a palm tree is found in a jungle.

Multiple Choice

The picture shows four layers of rock discovered near a road. The rock layers were uncovered when the road was built. Millions of years ago, this area was a large swamp. Now, it is so dry that it is almost a desert.

Each layer contains a fossil of a once-living plant or animal.

QUESTION: WHICH FOSSIL would be in layer W AND provide evidence that the environment has changed over time.

• fossil of a bear

• fossil of a frog

• fossil of a cactus

• fossil of a fish

Multiple Choice

The picture shows four layers of rock discovered near a road. The rock layers were uncovered when the road was built. Millions of years ago, this area was a large swamp. Now, it is so dry that it is almost a desert.

Each layer contains a fossil of a once-living plant or animal.

QUESTION: WHICH FOSSIL would be in layer X AND provide evidence that the environment has changed over time.

• fossil of a bear

• fossil of a frog

• fossil of a cactus

• fossil of a fish

Multiple Choice

The picture shows four layers of rock discovered near a road. The rock layers were uncovered when the road was built. Millions of years ago, this area was a large swamp. Now, it is so dry that it is almost a desert.

Each layer contains a fossil of a once-living plant or animal.

QUESTION: WHICH FOSSIL would be in layer Y AND provide evidence that the environment has changed over time.

• fossil of a bear

• fossil of a frog

• fossil of a cactus

• fossil of a fish

Multiple Choice

The picture shows four layers of rock discovered near a road. The rock layers were uncovered when the road was built. Millions of years ago, this area was a large swamp. Now, it is so dry that it is almost a desert.

Each layer contains a fossil of a once-living plant or animal.

QUESTION: WHICH FOSSIL would be in layer Z AND provide evidence that the environment has changed over time.

• fossil of a bear

• fossil of a frog

• fossil of a cactus

• fossil of a fish

Multiple Select

Millions of years ago, a huge flood covered a large area. Rivers overflowed. Land was covered with deep water.

Which two statements provide evidence that fish survived the flood but dinosaurs did not?

• Fossil fish would appear in the fossil record in layers that are younger than the layer in which the flood occurred.

• No dinosaur fossils would appear below the layer in which the flood occurred.

• No dinosaur fossils would appear above the layer in which the flood occurred.

Multiple Choice

Look at the picture. Choose the correct words to finish the sentences.

The armored fish in the picture appeared after / before

the trilobites appeared.

• after

• before

Multiple Choice

Look at the picture. Choose the correct words to finish the sentences.

The dinosaur in the picture appeared after / before

the wooly mammoth appeared.

• after

• before

VOCABULARY

ARGUE: TO MAKE CLAIMS SUPPORTED BY EVIDENCE

OBEJECTIVE

WE CAN Use fossil data to argue how some living things have responded to climate changes.