Question

A team of archaeologists excavating a sedimentary rock layer come across some primitive hunting tools used by early humans. As the dig progresses, they unearth the fossilized remains of a dinosaur from another layer of the sedimentary rock. Why do these discoveries indicate that the rocks were formed over millions of years?
Responses
A Early humans appeared on Earth about a million years ago.Early humans appeared on Earth about a million years ago.
B Humans and dinosaurs coexisted about a million years ago.Humans and dinosaurs coexisted about a million years ago.
C Dinosaurs became extinct millions of years before humans appeared.Dinosaurs became extinct millions of years before humans appeared.
D Humans hunted dinosaurs and were responsible for their extinction.

Answer 1

C

Explanation: Sedimentary layers form in sequence (the principle of superposition): deeper layers are older, higher layers are younger. Dinosaurs died out about 65 million years ago, long before humans appeared (the Homo lineage appears only a few million years ago). Finding dinosaur fossils in a lower layer and human tools in an upper layer therefore indicates the rocks accumulated over millions of years. Options A, B, and D are incorrect for the reasons above.