Three jawed pedicellariae occur in

Options

A. Asteroidea
B. Crinoidea
C. Echinoidea
D. Holothuroidea

Answer

To answer the question "Three jawed pedicellariae occur in," we will analyze the options provided and the characteristics of pedicellariae in different classes of Echinoderms.

### Step-by-Step Solution:

1. **Understanding Pedicellariae**:
- Pedicellariae are small, pincer-like structures found in some echinoderms. They serve various functions, including defense and cleaning the body surface.

2. **Identifying the Classes**:
- The options given are:
- Asteroidea (sea stars)
- Crinoidea (sea lilies)
- Echinoidea (sea urchins)
- Holothuroidea (sea cucumbers)

3. **Analyzing Asteroidea**:
- In Asteroidea, the pedicellariae are not three-jawed; they are typically forcep-like. Therefore, this option is incorrect.

4. **Analyzing Crinoidea**:
- Crinoidea lacks pedicellariae entirely. Thus, this option is also incorrect.

5. **Analyzing Holothuroidea**:
- Holothuroidea does not possess pedicellariae. This option is incorrect as well.

6. **Analyzing Echinoidea**:
- Echinoidea, which includes sea urchins, is known for having three-jawed pedicellariae. This makes this option the correct answer.

### Conclusion:
The correct answer to the question "Three jawed pedicellariae occur in" is **Echinoidea**.

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