A parietal eye is found in

Options

A. Sphenodun
B. Uromastix
C. Garden lizard
D. Marine Turtle.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the organism that possesses a parietal eye.

2. **Analyzing the Options**: The options provided are:
- Option 1: Sphenodon
- Option 2: Euromastrix
- Option 3: Garden Lizard
- Option 4: Marine Turtle

3. **Evaluating Each Option**:
- **Euromastrix**: This is a type of lizard, but it does not have a parietal eye. Therefore, this option is incorrect.
- **Garden Lizard**: Commonly found around homes, garden lizards only have two regular eyes and do not possess a parietal eye. Thus, this option is also incorrect.
- **Marine Turtle**: Marine turtles live in water where light is less intense, and they do not have a specialized parietal eye. Hence, this option is incorrect as well.

4. **Identifying the Correct Option**: The only remaining option is:
- **Sphenodon**: Also known as Tautara, this reptile is endemic to New Zealand and is not classified as a lizard despite its lizard-like appearance.

5. **Understanding the Parietal Eye**:
- The parietal eye, also referred to as the "third eye," is located on the top of the head between the two regular eyes of Sphenodon.
- It is a photoreceptive organ that can detect light but does not provide complete vision. It helps in regulating circadian rhythms through its connection to the pineal gland.

6. **Conclusion**: Based on the analysis, the correct answer to the question is **Sphenodon**.

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