Fossils as Evidence

Question 1

A scientist discovers three clues in one layer of rock: 1. Tiny, overlapping scales that belong to a fish. 2. Small, curved ripple marks preserved in the rock. 3. An imprint of a broad‑leaf plant. Which statement best explains what this tells us about the ancient world where these fossils were formed?

Accepted Answer

The rock formed in a shallow, calm body of water near land where both fish and plants lived.

Answer

The area was a dry desert, and the fish scales were blown there by wind after the fish died.

Answer

The fish was a land‑dwelling animal that ate the plants, and the ripple marks were made by wind.

Answer

The plant lived deep underwater, and the fish was a giant predator that ate only other fish.

Question 2

Scientists examined three fossils found together in the same rock layer: a fossilized fish with scales, a fossilized shell of a marine clam, and a fossilized leaf that has a thick, waxy surface. Which environment most likely existed where these organisms lived?

Accepted Answer

A shallow ocean floor

Answer

A desert with sand dunes

Answer

A freshwater lake

Answer

A mountain meadow

Question 3

Paleontologists uncover a fossilized sea creature with a hard, curved shell that looks very much like the shell of a living horseshoe crab they catch on a beach today. Which statement best explains how comparing this fossil to the living animal helps scientists understand how life has changed over millions of years?

Accepted Answer

The similarity shows the fossil and the modern horseshoe crab share a common ancestor, so some body plans have stayed similar while many others have changed over time.

Answer

Because they look alike, the fossil and the modern horseshoe crab must have lived at the same time, meaning the ancient creature is not extinct.

Answer

The fossil must actually be a modern horseshoe crab that was somehow buried, so no evolutionary change is needed to explain the find.

Answer

The resemblance only tells scientists that the ancient creature lived in water, but it does not provide any information about how life has changed.

Try three questions

Scientists examined three fossils found together in the same rock layer: a fossilized fish with scales, a fossilized shell of a marine clam, and a fossilized leaf that has a thick, waxy surface. Which environment most likely existed where these organisms lived?

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