Who had given the hemichordata the status of an independent invertebrate phylum?

Options

A. Vander horst
B. Dawydoff, Marcus
C. Hayman
D. All of these

Answer

To answer the question "Who had given the hemichordata the status of an independent invertebrate phylum?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hemichordata**:
- Hemichordata is a phylum of marine animals that are considered to be deuterostomes. They share some characteristics with echinoderms and chordates.

2. **Identifying Key Contributors**:
- Several scientists have contributed to the classification of Hemichordata as an independent phylum. The notable contributors mentioned are:
- Hyman (1959)
- Diedoff and Marcus (1946)
- Vanderhorst

3. **Hyman's Contribution**:
- In 1959, Hyman classified Hemichordata as deuterostomes, emphasizing their marine nature and functional similarities with other deuterostomes.

4. **Diedoff and Marcus's Contribution**:
- Diedoff and Marcus in 1946 proposed that Hemichordata are closely related to echinoderms, supporting their classification as a distinct phylum.

5. **Vanderhorst's Contribution**:
- Vanderhorst also supported the idea that Hemichordata should be recognized as an independent phylum, aligning with the views of Hyman and Diedoff & Marcus.

6. **Conclusion**:
- All these scientists contributed to the recognition of Hemichordata as an independent invertebrate phylum. Therefore, the correct answer to the question is "all of these".

### Final Answer:
The status of Hemichordata as an independent invertebrate phylum was given by Hyman, Diedoff and Marcus, and Vanderhorst. Thus, the answer is **Option D: all of these**.

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