Ordovician Period

The Ordovician Period is the second period of the Paleozoic Era, spanning approximately 485.4 to 443.8 million years ago. It is named after the Celtic tribe of the Ordovices and is known for significant evolutionary events and changes in Earth's geography and climate.

Key Events and Features:

• Diversification of Life: The Ordovician saw a remarkable diversification of marine life, including the emergence of the first jawless fish and the proliferation of invertebrates such as brachiopods, bryozoans, and trilobites.
• Ordovician-Silurian Extinction Event: At the end of the Ordovician, the second-largest mass extinction in Earth's history occurred, leading to the disappearance of many marine species, particularly those with calcium carbonate shells.
• Geographical Changes: During the Ordovician, the supercontinent Gondwana continued to drift southward, and the formation of the Iapetus Ocean influenced the distribution of landmasses.
• Climate and Environment: The climate during the Ordovician was generally warm and stable, and the period is characterized by extensive shallow seas and a lack of polar ice caps.

Study Guide:

1. What are the key characteristics of the Ordovician Period?
2. Describe the significant evolutionary events that occurred during the Ordovician.
3. Explain the impact of the Ordovician-Silurian extinction event.
4. Discuss the geological and climatic factors that shaped the Ordovician Period.
5. Compare the life forms and ecosystems of the Ordovician with those of other geological periods.

[Ordovician] Related Worksheets and Study Guides:

• Geologic timeScience • Eighth Grade