Which one of the following is not a living fossil
Or
Missing link in evolution is

Options

A. Limulus
B. Peripatus
C. Sphenodon
D. Archaeopteryx

Answer

To determine which of the following options is not a living fossil or is a missing link in evolution, we need to analyze each option provided: Limulus, Peripatus, Sphenodon, and Archaeopteryx.

### Step-by-Step Solution:

1. **Understanding Living Fossils**:
- Living fossils are species that have remained relatively unchanged over long geological periods and resemble species known only from the fossil record.

2. **Analyzing the Options**:
- **Limulus**: Commonly known as the horseshoe crab, it is often referred to as a living fossil because it has existed for hundreds of millions of years with little change.
- **Peripatus**: This is a genus of velvet worms, which are also considered living fossils due to their ancient lineage and minimal evolutionary change.
- **Sphenodon**: Also known as the tuatara, it is a reptile that has existed for over 200 million years and is considered a living fossil.
- **Archaeopteryx**: This is a well-known fossil that represents an early stage in the evolution of birds. It lived during the Jurassic period, around 180 million years ago.

3. **Identifying the Missing Link**:
- Archaeopteryx is not a living fossil; it is a fossilized species that provides evidence of the transition between dinosaurs and modern birds. Thus, it is considered a missing link in evolution.

4. **Conclusion**:
- Based on the analysis, the answer to the question "Which one of the following is not a living fossil?" or "Which among the following is a missing link in evolution?" is **Archaeopteryx**.

### Final Answer:
**Archaeopteryx lithographica** is not a living fossil and is considered a missing link in evolution.

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