Buried Deep and Fast: teacher key

Fossils, grade 7 edition, written for 7th grade. Few remains last long enough to become fossils. Read how burial, minerals and time save some, what the fossil record leaves out, and how a name for Oviraptor turned out to be a mistake.

Read the book. Print this page for the key.

Questions and answers

1. Using the pages, why does burial help remains last?
   • It slows decay because there is little oxygen (answer)
   • It makes bones lighter
   • It adds soft parts
2. In permineralization, what happens to the fossil compared with the original?
   • It ends up heavier (answer)
   • It ends up lighter
   • It ends up softer
3. A specimen is dated by the rocks around it. Which kind of dating gives its age in years?
   • Radiometric dating (answer)
   • Relative dating
   • Tracking by stride
4. Some preserved remains are 8,000 years old. By the common rule on the pages, are they counted as fossils?
   • Yes, because they are preserved
   • No, because they are younger than 10,000 years (answer)
   • Only if they were buried in ice
5. As of November 2026, what share of all species that ever lived are thought to be extinct?
   • Less than 1 percent
   • About half
   • More than 99 percent (answer)

Words

• subfossils: partly fossilised remains
• permineralization: minerals filling pores
• radiometric: using radioactive clocks
• extinct: died out
• brooding: sitting on eggs