Why the fossil record has gaps, and what fossils say about past environments

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   A classmate says shell fossils near a mountaintop show sea animals lived up there. Which reply fits NPS, by Esme's reading?

   • The rock formed under a sea and was lifted later
   • The shells are modern litter
   • Correct; sea animals lived on peaks
   • Correct; the shells crawled up the slope over many years
2. 2.

   A student says the fossil record shows each species that ever lived. Which reply fits NPS, by Jun's reading?

   • No; fossilizing is rare, so the record is incomplete
   • Yes; each species left at least one fossil
   • No; fossils show plants alone
   • Yes; soft-bodied life fossilizes easily
3. 3.

   A student calls a dinosaur trackway a body fossil. Which reply fits NPS, by Kira's reading?

   • It is a mold of a bone
   • Correct; tracks are part of the animal's body, just like bones
   • It is a cast of the skin
   • It is a trace fossil: a record of activity, not body parts
4. 4.

   Four rock cards, labeled A to D. A team wants Permian sea fossils. Which rock should they search first, by Luz's reading?

   • Cenozoic river sand from a recent riverbed
   • Marine limestone or shale of Permian age
   • A lava flow from 1 million years ago
   • Granite from deep magma
5. 5.

   Four plan cards, labeled A to D. Which plan best tests whether model fossil W lived near a shore, by Milo's reading?

   • Assume W lived where its rock sits today
   • Count W's teeth
   • Look for W on mountain peaks
   • Check the layer for ripple marks, footprints and shell fossils
6. 6.

   A cliff shows model fossils P, Q and R: P is a hollow shell print, Q a burrow, R a bone with minerals in its pores. Which list is right, by Ren's reading?

   • P a trace fossil, Q a cast, R a mold
   • P a mold, Q a trace fossil, R permineralized
   • P a cast, Q a trace fossil, R permineralized
   • P a mold, Q a body fossil, R a trace fossil
7. 7.

   Why are hard-shelled sea animals so common in the record compared with jellyfish, by Tala's reading (NPS)?

   • Few jellyfish fossils mean few jellyfish lived
   • Shells form fossils even unburied
   • Hard shells resist decay, and sea floors bury them fast
   • Jellyfish leave casts more often
8. 8.

   Which summary of fossilization fits NPS, by Zee's reading?

   • Rare; favored by hard parts and fast burial; record incomplete
   • Rare; favored by soft parts left in the open
   • Common; a gap means no life lived then
   • Common; most remains become fossils; record complete
9. 9.

   Four summary cards, labeled A to D. Which summary of what fossils show fits NPS, by Ari's reading?

   • Past life, its activities and its environments
   • Just the bones of large animals
   • The environment at that spot today, not the past
   • The exact day each animal lived
10. 10.

    “Cross-section:” Model layers: sea shells at the bottom, river fossils above, then a layer with no fossils on top. Which summary fits, by Bo's reading?

    • Sea, then river; the gap means nothing lived there
    • Both layers were laid down together by one flood in a single day
    • River, then sea; the gap means no life
    • Sea, then river; the top gap may be missing preservation