The period of fishes is

Options

A. Jurrasic
B. Devonian
C. Cretaceous
D. Silurian

Answer

To determine the period of fishes, we need to analyze the geological time scale and the evolution of fish.

### Step-by-Step Solution:

1. **Understanding Geological Time Scale**: The geological time scale is divided into eons, eras, periods, epochs, and ages. The periods are significant divisions that mark major events in the history of the Earth.

2. **Identifying the Relevant Periods**: The question provides four options:
- Jurassic
- Devonian
- Cretaceous
- Silurian

3. **Researching the Evolution of Fishes**: Fishes are believed to have originated during the Devonian period. This period is often referred to as the "Age of Fishes" because of the significant diversification and abundance of fish species during this time.

4. **Confirming the Time Frame of the Devonian Period**: The Devonian period lasted from approximately 410 to 360 million years ago. This timeframe is crucial as it aligns with the emergence and evolution of early fish.

5. **Eliminating Incorrect Options**:
- The Jurassic and Cretaceous periods are known for the dominance of dinosaurs and do not specifically mark the age of fish.
- The Silurian period does precede the Devonian and saw the early development of fish, but it is not recognized as the primary period for fish evolution.

6. **Conclusion**: Based on the information gathered, the correct answer to the question "The period of fishes is" is **Devonian**.

### Final Answer:
The period of fishes is **Devonian**.

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