Question

Which of the following time boundaries correspond(s) to major mass extinction events?

• A. Cretaceous - Paleogene
• B. Paleogene - Neogene
• C. Permian - Triassic
• D. Precambrian - Cambrian

Hint:

Mass extinction events such as the K-Pg and P-Tr extinctions had profound impacts on biodiversity and were caused by catastrophic events like asteroid impacts and volcanic activity.

Answer 1

The Correct Option is A, C

Step 1: Identifying Mass Extinction Events
Mass extinction events are characterized by a rapid loss of species across the globe. The Cretaceous–Paleogene and Permian–Triassic boundaries are the most significant mass extinction events in Earth's history.

Step 2: The Cretaceous–Paleogene Event
The Cretaceous–Paleogene (K–Pg) extinction occurred about 66 million years ago and is most famous for the extinction of the dinosaurs. This event was likely caused by a combination of volcanic activity and an asteroid impact.

Step 3: The Permian–Triassic Event
The Permian–Triassic (P–Tr) extinction, which occurred about 252 million years ago, is the largest known extinction event, wiping out approximately 90% of Earth's species. It was caused by massive volcanic activity, climate change, and ocean acidification.

Step 4: Other Boundaries
The Paleogene–Neogene boundary does not correspond to a major mass extinction event.
The Precambrian–Cambrian boundary marks the beginning of abundant fossil records but is not associated with a mass extinction event.