Which of the following order of gymnosperm is totally become extinct ?

Options

A. Cycadales
B. Ginkgoales
C. Gnetales
D. Cycadofilicales

Answer

**Step-by-Step Solution:**

1. **Understanding Gymnosperms**: Gymnosperms are a group of seed-producing plants that includes conifers, cycads, ginkgo, and gnetophytes. They are characterized by having seeds that are not enclosed in an ovary (naked seeds).

2. **Identifying the Orders**: The question lists four orders of gymnosperms:
- Psychedelis
- Gyncoelis
- Nitelis
- Psychodophilicace (also known as Pteridosperms)

3. **Researching Extinction**: To determine which of these orders has become totally extinct, we need to look at the history of these orders:
- **Psychedelis**: Not widely recognized as extinct.
- **Gyncoelis**: This order is associated with Ginkgo, which is not extinct.
- **Nitelis**: This order is also not known to be extinct.
- **Psychodophilicace (Pteridosperms)**: This order is known to have flourished during the Carboniferous era and is recognized as having become extinct around the Mesozoic era.

4. **Conclusion**: Based on the information, the order that has totally become extinct is **Psychodophilicace (Pteridosperms)**.

5. **Final Answer**: The correct answer to the question is **Psychodophilicace**.

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