Living fossil reptile is

Options

A. Turtle
B. Snake
C. Sphenodon
D. Crocodile

Answer

### Step-by-Step Solution:

1. **Understanding the Term "Living Fossil":**
- A living fossil is a term used to describe a species that has remained relatively unchanged over a long period of geological time and has no close living relatives.

2. **Identifying the Options:**
- The question provides four options:
1. Turtle
2. Snake
3. Spenodon
4. Crocodile

3. **Analyzing Each Option:**
- **Turtle:** Turtles have a long evolutionary history but are not the only surviving lineage from the time of the dinosaurs.
- **Snake:** Snakes evolved later than some of the other reptiles and do not fit the criteria for living fossils.
- **Crocodile:** Crocodiles are ancient but have undergone significant evolutionary changes since the time of the dinosaurs.

4. **Focusing on Spenodon:**
- Spenodon, also known as Tuatara, is a genus of reptiles endemic to New Zealand.
- It is the only surviving member of an ancient group of reptiles that thrived during the age of dinosaurs.

5. **Conclusion:**
- Since Spenodon has existed since the time of the dinosaurs and has no close living relatives, it is classified as a living fossil. Therefore, the correct answer is **Spenodon**.

### Final Answer:
The living fossil reptile is **Spenodon**.

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