Question

The image above shows where a team of paleontologists has dug down into the earth through several layers of sedimentary rock labeled A through D.
If $"x"$ shows where the scientists found fossils of two closely related species of dinosaur, in which layer should they expect to find fossils from their most recent common ancestor?

• A. A
• B. B
• C. C
• D. D

Answer 1

Answer: (B)

B

Fossils are organisms or their remains that get buried in the soil. With time new layers of soil get deposited on the remains and the organism is buried deeper. Therefore chronologically a fossil of recent time will be closer to the surface while the older will be deeper.

Here, the fossil x is at layer C, so its closest recent ancestor will be a layer below, that is layer B

So, the correct answer is 'B'