Cretaceous-Paleogene (K-Pg) Extinction Event

The Cretaceous-Paleogene (K-Pg) extinction event, also known as the Cretaceous-Tertiary (K-T) extinction, was a mass extinction event that occurred approximately 66 million years ago. It marked the end of the Cretaceous period and the beginning of the Paleogene period.

Causes of the K-Pg Extinction

The K-Pg extinction is widely believed to have been caused by a combination of several factors, including:

• Impact Event: The impact of a massive asteroid or comet is thought to have triggered widespread environmental changes, including wildfires, tsunamis, and the release of debris into the atmosphere.
• Climate Change: The impact event likely caused a significant cooling of the Earth's climate due to the blocking of sunlight by debris in the atmosphere, leading to a disruption of global ecosystems.
• Volcanic Activity: Intense volcanic activity, particularly the Deccan Traps in India, may have also contributed to environmental changes and global climate disruption.

Effects of the K-Pg Extinction

The K-Pg extinction had profound effects on the Earth's biodiversity, leading to the mass extinction of numerous plant and animal species, including the dinosaurs. It also paved the way for the rise of mammals and the eventual dominance of humans on the planet.

Study Guide

To prepare for a study of the Cretaceous-Paleogene extinction event, consider the following key points:

1. Understand the geological timeline, including the Cretaceous and Paleogene periods.
2. Learn about the possible causes of the K-Pg extinction, including the impact event, climate change, and volcanic activity.
3. Explore the effects of the extinction event on global biodiversity and the subsequent rise of mammals.
4. Examine the evidence for the extinction event, including geological records, fossils, and impact craters.

By mastering these concepts, you will gain a comprehensive understanding of the Cretaceous-Paleogene extinction event and its significance in the history of life on Earth.