The first mammal appeared in `:`

Options

A. jurassic period
B. triassic period
C. permian period
D. cretaceous period

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks when the first mammals appeared in geological history.

2. **Identifying the Relevant Periods**: To answer this, we need to know about the different geological periods. The main periods of interest here are the Permian, Triassic, Jurassic, and Cretaceous periods.

3. **Origin of Mammals**: Research indicates that mammals originated during the Triassic period. This is crucial information as it directly answers the question.

4. **Connection to Other Species**: It is important to note that mammals evolved from a group of reptiles known as Synapsida, which exhibited early mammalian characteristics. These synapsids were present during both the Permian and Triassic periods.

5. **Conclusion**: Since the question specifically asks for the first appearance of mammals, the correct answer is the Triassic period, as this is when true mammals began to emerge.

6. **Final Answer**: The first mammal appeared in the **Triassic period**.

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