Matching Rocks by Their Fossils: teacher key

Fossils, grade 9 edition, written for 9th grade. Fossils helped geologists match rock layers across distances and map a nation. Read how correlation, ash layers and tracks work, and what Tiktaalik and Archaeopteryx show.

Read the book. Print this page for the key.

Questions and answers

1. What did William Smith become the first person to map?
   • The oceans of the world
   • The tracks of a herd
   • The geology of an entire nation, England and Wales (answer)
2. What is tracing rocks and fossils from one place to another called?
   • Permineralization
   • Correlation (answer)
   • Succession
3. Suppose a fossil lies in a layer above an ash layer dated to 100 million years ago and below an ash layer dated to 90 million years ago. Using the pages, about how old is the fossil?
   • Older than 100 million years
   • Younger than 90 million years
   • Between 90 and 100 million years old (answer)
4. As of November 2026, what do scientists still not know about Archaeopteryx?
   • Whether it could fly or only glide (answer)
   • Whether it had feathers
   • Whether it had a wishbone
5. Why is Tiktaalik better called a transitional form than a missing link?
   • It had no fins
   • It shows a mix of fish and four-legged traits (answer)
   • It lived on land only

Words

• correlation: matching rocks
• radiometric: using radioactive clocks
• transitional: in between
• trackway: line of tracks
• Plesiosaurus: ancient sea reptile