Mass extinction at the end of Mesozoic era was probably due to

Options

A. Continental drift
B. Massive glaciation
C. Collision of earth with large meteorite
D. Change in earth's orbit.

Answer

### Step-by-Step Solution:

1. **Understanding the Mesozoic Era**:
- The Mesozoic Era is divided into three periods: Triassic, Jurassic, and Cretaceous. It spanned from approximately 252 million years ago to 66 million years ago.
- This era is often referred to as the "Age of Reptiles" because it was dominated by dinosaurs and other reptiles.

2. **Identifying the Event of Mass Extinction**:
- At the end of the Mesozoic Era, a significant event occurred known as the mass extinction event, which led to the extinction of a large number of species, including the dinosaurs.

3. **Evaluating Possible Causes**:
- The question provides four possible causes for this mass extinction:
- Continental drift
- Massive glaciation
- Collision of Earth with a large meteorite
- Change in Earth's orbit

4. **Analyzing Each Cause**:
- **Continental Drift**: While continental drift was occurring, it is not considered a direct cause of the mass extinction at the end of the Mesozoic Era.
- **Massive Glaciation**: Although glaciation events have affected life on Earth, they are not recognized as the primary cause of the mass extinction at this time.
- **Collision of Earth with a Large Meteorite**: This is widely accepted as the main cause of the mass extinction event. The impact would have caused catastrophic environmental changes, leading to the extinction of many species.
- **Change in Earth's Orbit**: Changes in Earth's orbit do affect climate over long periods, but they are not considered a direct cause of the mass extinction at the end of the Mesozoic Era.

5. **Conclusion**:
- After evaluating the options, the most probable cause of the mass extinction at the end of the Mesozoic Era is the **collision of Earth with a large meteorite**.

### Final Answer:
The mass extinction at the end of the Mesozoic era was probably due to the **collision of Earth with a large meteorite**.

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