Why the fossil record has gaps, and what fossils say about past environments
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
A classmate says shell fossils near a mountaintop show sea animals lived up there. Which reply fits NPS, by Esme's reading?
- Correct; sea animals lived on peaks
- The shells are modern litter
- The rock formed under a sea and was lifted later
- Correct; the shells crawled up the slope over many years
A student says the fossil record shows each species that ever lived. Which reply fits NPS, by Jun's reading?
- Yes; each species left at least one fossil
- No; fossilizing is rare, so the record is incomplete
- No; fossils show plants alone
- Yes; soft-bodied life fossilizes easily
A student calls a dinosaur trackway a body fossil. Which reply fits NPS, by Kira's reading?
- 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
- It is a mold of a bone
Four plan cards, labeled A to D. Which plan best tests whether model fossil W lived near a shore, by Milo's reading?
- Look for W on mountain peaks
- Count W's teeth
- Check the layer for ripple marks, footprints and shell fossils
- Assume W lived where its rock sits today
Fossil-rich layers sit in a basin, but a nearby upland has few. Which plan explains the difference, by Noah's reading?
- Assume the basin animals were larger
- Treat the upland's few fossils as a complete record
- Compare how much sediment built up in each place
- Assume the upland had no life
Layer M holds fish fossils; layer N above holds land plant fossils and mud cracks. Which claim does the evidence best support, by Pia's reading?
- Water gave way to land that sometimes dried out
- Land gave way to water
- The fish lived among the plants on land
- Both layers formed at the same time, in one flood
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 body fossil, R a trace fossil
- P a mold, Q a trace fossil, R permineralized
- P a cast, Q a trace fossil, R permineralized
Why are hard-shelled sea animals so common in the record compared with jellyfish, by Tala's reading (NPS)?
- Shells form fossils even unburied
- Hard shells resist decay, and sea floors bury them fast
- Jellyfish leave casts more often
- Few jellyfish fossils mean few jellyfish lived
Which summary of fossilization fits NPS, by Zee's reading?
- Rare; favored by soft parts left in the open
- Common; a gap means no life lived then
- Common; most remains become fossils; record complete
- Rare; favored by hard parts and fast burial; record incomplete
“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?
- River, then sea; the gap means no life
- Sea, then river; the gap means nothing lived there
- Both layers were laid down together by one flood in a single day
- Sea, then river; the top gap may be missing preservation
