Which of the following is not amongst the evolutionary line of mammals?

Options

A. Therapsids
B. Pelycoasurs
C. Synapsids
D. Sauropsids

Answer

To determine which of the following is not amongst the evolutionary line of mammals, we can follow a step-by-step analysis of the evolutionary tree of mammals and reptiles.

### Step 1: Understand the Evolutionary Tree
- The evolutionary tree illustrates the relationships between different groups of organisms. For mammals, we need to focus on the lineages that lead to them.

### Step 2: Identify Early Reptiles
- Early reptiles existed around 350 million years ago. These reptiles branched into two main groups: Sauropsida and Synapsida.

### Step 3: Explore Synapsida
- Synapsida is the lineage that eventually led to mammals. Within Synapsida, we have:
- **Pelycosaurus**: An early group of Synapsids.
- **Therapsids**: Descendants of Pelycosaurus, which are more closely related to mammals.

### Step 4: Explore Sauropsida
- Sauropsida is the lineage that led to reptiles, including birds and dinosaurs. It does not contribute to the evolutionary line of mammals.

### Step 5: Analyze the Options
- The options provided are:
1. Therapsida
2. Pelycosaurus
3. Synapsida
4. Sauropsida

### Step 6: Identify the Incorrect Option
- Among these options, **Sauropsida** is the one that does not belong to the evolutionary line of mammals. It is associated with reptiles instead.

### Conclusion
- The correct answer to the question "Which of the following is not amongst the evolutionary line of mammals?" is **Sauropsida**.

---