Fossils of early vascular plants have been discovered in the rocks of

Options

A. Cambrian
B. Silurian
C. Devonian
D. Jurassic.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the geological period in which fossils of early vascular plants have been discovered. Vascular plants are those that have specialized tissues (xylem and phloem) for transporting water and nutrients.

2. **Identifying the Options**: The options provided are Cambrian, Silurian, Devonian, and Jurassic. We need to determine which of these periods is associated with the earliest fossil records of vascular plants.

3. **Researching Fossil Records**: The first fossil records of vascular plants indicate that these plants appeared during the Silurian period. This is a crucial piece of information as it directly answers the question.

4. **Identifying Early Vascular Plants**: The earliest known representatives of vascular plants are placed in the genus Cucsonia. These plants had simple branching patterns and were characterized by branches that ended in flattened sporangia.

5. **Evaluating Each Option**:
- **Cambrian**: This period is known for the emergence of simple life forms, not vascular plants. Therefore, it is incorrect.
- **Silurian**: This is the correct answer as it is when the first vascular plants were discovered.
- **Devonian**: While this period saw further diversification of vascular plants, it is not the period of their first appearance, making it incorrect.
- **Jurassic**: This period is much later and does not pertain to the earliest vascular plants, thus it is also incorrect.

6. **Conclusion**: Based on the information gathered, the correct answer to the question is the **Silurian period**.

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