In which period of paleozoic era first vertebrate appeared.

Options

A. Ordovician
B. Devoninan
C. Silurian
D. Mississipian

Answer

To determine the period of the Paleozoic era in which the first vertebrates appeared, we can follow these steps:

1. **Understand the Paleozoic Era**: The Paleozoic era spans from approximately 542 million years ago to 251 million years ago. It is characterized by significant geological, climatic, and biological changes.

2. **Identify the Periods of the Paleozoic Era**: The Paleozoic era is divided into several periods: Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, and Permian.

3. **Focus on the Appearance of Vertebrates**: Vertebrates are a group of animals that have a backbone. The question specifically asks about the first appearance of vertebrates.

4. **Research the Timeline of Vertebrate Evolution**: The first vertebrates are believed to have appeared during the Ordovician period. This period is known for the diversification of marine life and the emergence of early fish-like vertebrates.

5. **Select the Correct Answer**: Based on the information gathered, the first vertebrates appeared in the Ordovician period of the Paleozoic era.

Final Answer: The first vertebrates appeared in the Ordovician period of the Paleozoic era.

---