Fossils and Evidence of Past Life — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. In Grade 3 science, a palm tree fossil found in the Arctic shows the climate was once warm there.
Climate means long-term weather; palms need warmth, so the Arctic climate must have been warm.
2. In Grade 3 science, a fish fossil in a dry desert tells us a sea once covered that land.
Fish fossils in deserts are evidence that the area was once covered by an ancient sea.
3. In Grade 3 science, fern fossils in coal suggest the area was once a warm, wet swamp.
Coal forms from dense, warm, wet swamps where ferns and other plants grew thick.
4. In Grade 3 science, dinosaur bones found in a backyard prove that dinosaurs once lived there.
Fossils usually form where an animal died, so bones mean the animal once lived there.
5. In Grade 3 science, coral fossils on a mountain show the peak was once under the ocean.
Corals live underwater, so their fossils on a mountain mean the land was once ocean floor.
6. In Grade 3 science, plants and animals that no longer live on Earth are called extinct.
Extinct species have died out completely and are known today mostly through fossils.
7. In Grade 3 science, fossils show us how Earth's environment has changed over many millions of years.
Fossils record past environments, showing that land, water, and climate have all changed.
8. In Grade 3 science, mammoth fossils in icy ground suggest the area had a very cold climate.
Mammoths had thick fur for cold weather, so their fossils point to cold past climates.
9. In Grade 3 science, layers of rock with fossils are read like pages of Earth's history book.
Rock layers store fossils in order, giving scientists a timeline of Earth's history.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Palm fossil in Arctic
→ Once a warm climate
Once a warm climate
Fish fossil in desert
→ Once a shallow sea
Once a shallow sea
Fern fossil in coal
→ Once a swampy forest
Once a swampy forest
Coral fossil on mountain
→ Once an ocean floor
Once an ocean floor
Each fossil needs a specific past environment, so palms = warm, fish = sea, ferns = swamp, corals = ocean floor.