Only one order of amphibians have exoskeleton (internal scales)

Options

A. Urodela
B. Cauda
C. Gymnophiona
D. Anura

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the order of amphibians that have an exoskeleton or internal scales.

2. **Identifying Amphibian Orders**: We need to consider the different orders of amphibians:
- **Eurydela**: This order has cutaneous (moist) skin and does not have internal scales.
- **Caudata**: This order, which includes salamanders, also has cutaneous skin and lacks scales.
- **Gymnophiona**: This order, also known as Apoda, consists of limbless amphibians. They possess dermal scales that are modified for protection.
- **Anura**: This order includes frogs and toads, which have moist skin and do not have scales.

3. **Analyzing the Information**: From the information provided, we see that only Gymnophiona has dermal scales that serve as an exoskeleton for protection.

4. **Conclusion**: The order of amphibians that has an exoskeleton (internal scales) is **Gymnophiona**.

5. **Final Answer**: The correct order is **Gymnophiona**.