Practice problem

Fossils (Evidence of Evolution) — Overview & Examples

The image displays a paleontologist at the top of the cliff. On the cliff side are layers of rock. Layer A is light brown. Layer B is dark brown. Layer C is red. Layer D is green. Layer A is the highest, and layer D is the lowest.

Imagine you are a paleontologist that specializes in stratigraphy. Stratigraphy is determining the age of a fossil based on the "layer" of stone or sediment that it is found in. You have determined that the rock you are studying has four layers, A, B, C, and D. Which of these layers is most likely to be the oldest layer?