To solve this problem, we need to understand the principle of superposition in geology. This principle states that in an undisturbed sequence of sedimentary rocks, each layer is older than the one above it and younger than the one below it.
Let's break down the rock layers from oldest to youngest:
1.
Siltstone (oldest) - Contains fossils of crocodile eggs and a leaf from a palm tree.
2.
Sandstone - No fossils mentioned.
3.
Limestone - Contains a fossil of a clam.
4.
Shale (youngest) - Contains a fossil of a fish.
Since the shale layer is the youngest, the organism that was alive most recently would be the one found in this layer. The shale layer contains a fossil of a fish.
Therefore, the organism that was alive most recently is the fish whose body was fossilized.
Final Answer: the fish whose body was fossilized
Parent Tip: Review the logic above to help your child master the concept of rock layers worksheet.
