The phylum which was earlier considered as a subphylum under chordata but now placed as a separate phylum, in non-chordates is

Options

A. Protochordata
B. hemichordata
C. Cephalochordata
D. Vertebrate

Explanation

To solve the question regarding the phylum that was previously considered a subphylum under Chordata but is now classified as a separate phylum in non-chordates, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a phylum that was once classified as a subphylum of Chordata but is now recognized as a separate phylum within non-chordates.

2. **Review the Options**: The options provided are:
- Protochordata
- Hemichordata
- Cephalochordata
- Vertebrates

3. **Analyze Each Option**:
- **Protochordata**: This term refers to a group of organisms that are considered to be primitive chordates. They are not classified as a separate phylum but rather as a group within Chordata. Thus, this option is incorrect.
- **Hemichordata**: This phylum was indeed once classified under Chordata but is now recognized as a separate phylum in non-chordates. This option is correct.
- **Cephalochordata**: Members of this group are true chordates, characterized by having a notochord. Therefore, this option is incorrect.
- **Vertebrates**: This group includes animals with a vertebral column and is classified under Chordata. Hence, this option is also incorrect.

4. **Conclusion**: Based on the analysis, the correct answer to the question is **Hemichordata**.

### Final Answer:
The phylum which was earlier considered as a subphylum under Chordata but now placed as a separate phylum in non-chordates is **Hemichordata**.

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