Which of these animals has not evolved from Sauropsids ?

Options

A. Tuataras
B. Birds
C. Mammals
D. Lizards

Answer

To determine which of the listed animals has not evolved from sauropsids, we need to analyze the evolutionary lineage of each option provided.

### Step-by-Step Solution:

1. **Understanding Sauropsids**:
- Sauropsids are a group of amniotes that include reptiles and birds. They evolved from primitive amniotes around 350 million years ago.

2. **Identifying the Groups**:
- The early amniotes split into two main groups:
- **Synapsids**: This group eventually gave rise to mammals.
- **Sauropsids**: This group gave rise to reptiles and birds.

3. **Analyzing the Options**:
- **Tuatara**: This is a type of reptile and is considered to have evolved from sauropsids.
- **Birds**: Birds are also descendants of sauropsids.
- **Mammals**: Mammals evolved from synapsids, not sauropsids.
- **Lizards**: Lizards are reptiles and have evolved from sauropsids.

4. **Conclusion**:
- Since mammals evolved from synapsids and not from sauropsids, the correct answer to the question is **mammals**.

### Final Answer:
**Mammals have not evolved from sauropsids.**