All of the following characters are shared by crocodiles and birds except

Options

A. Extraembryonic membranes
B. Dry skin
C. Homeothermy
D. Four - chambered heart

Answer

To solve the question, we need to identify the characteristics shared by crocodiles and birds, and then find the one that is not common to both.

### Step-by-Step Solution:

1. **Identify the Classes**:
- Crocodiles belong to the class Reptilia.
- Birds belong to the class Aves.

2. **List Common Characteristics**:
- Both crocodiles and birds are considered to have certain common features, such as:
- They both have a four-chambered heart.
- They both possess extra-embryonic membranes (like the amnion).
- They have dry skin (crocodiles have scaly skin, while birds have feathers that provide a waterproof barrier).

3. **Identify Unique Characteristics**:
- While both classes share several features, one key difference is that birds are endothermic (warm-blooded), while crocodiles are ectothermic (cold-blooded).
- Birds have feathers, which are unique to them and not found in crocodiles.

4. **Analyze the Options**:
- The question asks for the characteristic that is NOT shared by both.
- From the features listed, the one that stands out as not being shared is the presence of feathers, as only birds possess feathers.

5. **Conclusion**:
- Therefore, the characteristic that is not shared by crocodiles and birds is the presence of feathers.

### Final Answer:
The characteristic that is shared by crocodiles and birds except is the presence of feathers.