ASBOG Practice Exam

Which is the correct sequence of Paleozoic periods from oldest to youngest?

1. Permian; Carboniferous; Devonian; Silurian; Ordovician; Cambrian

2. Cambrian; Ordovician; Silurian; Devonian; Carboniferous; Permian

3. Devonian; Carboniferous; Silurian; Ordovician; Cambrian

4. Ordovician; Cambrian; Silurian; Devonian; Carboniferous; Permian

The correct answer is: Cambrian; Ordovician; Silurian; Devonian; Carboniferous; Permian

The correct sequence of Paleozoic periods from oldest to youngest is accurately represented by the choice that lists them as Cambrian; Ordovician; Silurian; Devonian; Carboniferous; Permian. This order is based on the standard geological time scale, which organizes the geological history of the Earth into distinct periods. The Cambrian period is the oldest of the Paleozoic era, marked by the "Cambrian Explosion," a significant period of rapid evolutionary development of life. Following the Cambrian, the Ordovician period is recognized for the diversification of marine life, like bryozoans and cephalopods. The Silurian period comes next, notable for the first appearance of vascular plants and significant coral reefs. As we progress through the Paleozoic, the Devonian is often referred to as the "Age of Fishes" due to the vast diversification of fish and the emergence of the first amphibians. The Carboniferous period is crucial for its extensive swampy forests, leading to significant coal deposits, followed by the Permian period, known for the supercontinent Pangaea and the mass extinction event that concluded the Paleozoic era. Understanding this order is essential as it forms the foundation of geological