Lesson 26

26

Mega Mammals and Ice Age Giants

Why did so many massive animals once roam the Earth, and where did they go?

Mammoths, giant ground sloths, and saber-toothed cats were among the large mammals of the Ice Age. This lesson considers their adaptations, the environments they occupied, and the possible causes of their disappearance.

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Key Ideas

  • The Ice Age began when Earth's climate cooled and glaciers spread.
  • Animals developed adaptations like thick fur, fat, and large bodies to survive.
  • Famous megafauna included mammoths, mastodons, giant sloths, and saber-toothed cats.
  • When the world warmed, many Ice Age giants went extinct.
  • Their descendants, like elephants, sloths, and big cats, still live today!

Spines

Vocabulary

  • Pleistocene Epoch: The time from about 2.6 million to 11,700 years ago, when ice sheets covered large parts of the world.
  • Glacier: A huge, slow-moving mass of ice that forms on land.
  • Megafauna: Very large animals, like woolly mammoths, giant ground sloths, and saber-toothed cats.
  • Adaptation: A feature or behavior that helps an animal survive, like thick fur or a layer of fat.
  • Migrate: To move from one place to another to find food or warmth.
  • Extinction: When a kind of living thing dies out completely.

Discussion Questions

  1. What patterns do you notice among the Ice Age animals?
    Sample Answer: Many were very large, many had thick fur or fat to stay warm, and they lived in cold, open grasslands or forests.
  2. How did adaptations help them survive the cold?
    Sample Answer: Thick fur and layers of fat kept heat inside, and large bodies lose heat more slowly. Some animals also migrated or hibernated during the coldest times.
  3. What evidence do we use to learn about animals that are extinct?
    Sample Answer: Scientists look for clues in fossils, bones, and even teeth.
  4. How might climate change have affected where animals could live?
    Sample Answer: When the world warmed, glaciers melted and grasslands became forests, so food sources changed or disappeared and animals had to move or adapt.
  5. What role might humans have played in their disappearance?
    Sample Answer: Humans hunted many Ice Age animals, which added pressure on top of the changing climate.

Digging Deeper

  1. Why did many Ice Age animals evolve very large body sizes?
    Sample Answer: Larger bodies lose heat more slowly, helping animals survive cold climates.
  2. What factors likely caused the extinction of Ice Age megafauna?
    Sample Answer: Warming climates reduced habitats, and human hunting increased pressure on large animals.