Monocondylic skull, dry skin and procoelous vertebrae are present in

Options

A. Amphibia
B. Reptilia
C. Birds
D. Mammals

Answer

To solve the question regarding which group of animals possesses a monocondylic skull, dry skin, and procoelous vertebrae, we can analyze each characteristic step by step.

### Step-by-Step Solution:

1. **Understanding Monocondylic Skull:**
- A monocondylic skull has one occipital condyle. This feature is typically found in reptiles and some other groups, but not in amphibians or mammals, which have two occipital condyles (dicondylic skull).

**Hint:** Look for the number of occipital condyles to identify the skull type.

2. **Identifying Dry Skin:**
- Dry skin is a characteristic feature of reptiles. In contrast, amphibians have moist skin, and birds have feathers that help in moisture retention. Therefore, the presence of dry skin suggests that we are looking at reptiles.

**Hint:** Consider the skin type of the animals to determine their habitat and adaptations.

3. **Understanding Procoelous Vertebrae:**
- Procoelous vertebrae are characterized by being concave on the anterior side and convex on the posterior side. This type of vertebrae is found in reptiles and some other groups, but not in amphibians or mammals.

**Hint:** Focus on the shape of the vertebrae to distinguish between different vertebrate groups.

4. **Conclusion:**
- Given that reptiles have a monocondylic skull, dry skin, and procoelous vertebrae, the correct answer to the question is reptiles.

**Final Answer:** The correct option is reptiles.