What is the most compelling piece of evidence that suggests that the dinosaurs were made extinct by the impact of an asteroid 65 million years ago?
A) a layer of sediment laid down at that time which is littered with dinosaur fossils
B) dinosaur fossils are found in rock layers older than 65 million years but not younger than 65 million years
C) a layer of sediment laid down at that time which is rich in the element Iridium (Ir), an element common in asteroids but less common on the Earth
D) the crater from this impact can still be seen in the deserts of Arizona

Question

Quizplus · Accepted Answer

The presence of a layer of sediment rich in the element Iridium (Ir) suggests that an asteroid impact occurred, as Ir is more common in asteroids than on Earth. Additionally, this layer coincides with the extinction of the dinosaurs, providing further evidence for the impact hypothesis. While options A and D provide additional support for the impact theory, they are not as compelling as the Ir layer. Option B is irrelevant to the impact hypothesis.

What Is the Most Compelling Piece of Evidence That Suggests