Second mass extinction occurred during

Options

A. Jurassic-cretaceous
B. Cretaceous-tertiary
C. Cretaceous-palaeocene
D. Both B and C

Answer

**Step-by-Step Text Solution:**

1. **Understanding Mass Extinctions**: First, we need to recognize what a mass extinction is. A mass extinction is a significant and rapid decrease in the biodiversity on Earth, where a large number of species become extinct in a relatively short period.

2. **Identifying the Second Mass Extinction**: The question specifically asks about the second mass extinction event. Historically, there have been five major mass extinctions, and the second one is known as the Late Devonian extinction.

3. **Time Frame of the Second Mass Extinction**: The Late Devonian extinction occurred over a prolonged period, roughly spanning from about 382 to 359 million years ago. This event is characterized by a series of extinctions that affected marine life, particularly the reef-building organisms.

4. **Impact of the Second Mass Extinction**: This extinction event led to the loss of about 75% of species, including many fish and invertebrates, and had a significant impact on the ecosystem of the time.

5. **Conclusion**: Therefore, the second mass extinction occurred during the Late Devonian period.

**Final Answer**: The second mass extinction occurred during the Late Devonian period.

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