Due to continental drift, the South American mammals were overidden by

Options

A. Australian marsupials
B. Sauropsids
C. Synapsids
D. North American fauna

Answer

**Step-by-Step Solution:**

1. **Understanding Continental Drift**: Continental drift refers to the gradual movement of the continents across the Earth's surface over geological time. This process has led to the separation of landmasses that were once joined together.

2. **Historical Context**: Approximately 250 million years ago, all continents were part of a supercontinent known as Pangaea. Over time, Pangaea began to break apart into smaller landmasses.

3. **Formation of Laurasia and Gondwana**: When Pangaea split, it formed two major landmasses: Laurasia in the northern hemisphere and Gondwana in the southern hemisphere. South America was part of Gondwana.

4. **Separation of Continents**: By about 65 million years ago, the continents had begun to separate further. This separation allowed for different species to evolve in isolation on different continents.

5. **Impact on Mammals**: As South America and North America drifted closer together, there was an exchange of species. The mammals that were native to South America were eventually overridden by mammals from North America due to this continental drift.

6. **Conclusion**: Therefore, the South American mammals were overridden by the North American mammals, which is the correct answer to the question.

**Final Answer**: The South American mammals were overridden by North American mammals.

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