Long hollow bones connected by passages are characteristics of

Options

A. Aves
B. mammals
C. Reptilia
D. land vertebrates

Explanation

**Step-by-Step Solution:**

1. **Identify the Characteristics**: The question mentions "long hollow bones connected by passages." This is a specific anatomical feature that can help us narrow down the options.

2. **Consider the Phyla**: The question asks which phylum exhibits these characteristics. We need to think about the different animal phyla and their skeletal structures.

3. **Focus on Aves (Birds)**: Among the various classes, birds (class Aves) are known for having hollow bones. These bones are designed to be lightweight, which is essential for flight.

4. **Understand Pneumatic Bones**: The hollow bones in birds are referred to as pneumatic bones. They contain air-filled cavities that reduce the overall weight of the skeleton, making flight easier.

5. **Compare with Other Phyla**: In contrast, mammals have solid bones filled with fatty tissue and bone marrow, while reptiles and other land vertebrates also have solid bones. This reinforces that the characteristic of hollow bones is unique to birds.

6. **Conclude the Answer**: Based on the above analysis, the correct answer to the question is that long hollow bones connected by passages are characteristic of the phylum Aves.

**Final Answer**: The long hollow bones connected by passages are characteristics of the phylum Aves (birds).

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