The Cretaceous-Paleogene (K-Pg) boundary, formerly known as the Cretaceous-Tertiary (K-T) boundary, marks the end of the Cretaceous Period and the beginning of the Paleogene Period. This boundary is significant because it represents a major mass extinction event that resulted in the extinction of the non-avian dinosaurs among other species.

Key Events and Characteristics

Formation of the Deccan Traps: Massive volcanic eruptions in what is now India during the late Cretaceous Period
Impact event: The Chicxulub impact, a large asteroid or comet impact in what is now the Yucatán Peninsula in Mexico, which is believed to have contributed to the mass extinction event
Mass extinction: Approximately 75% of all species, including the dinosaurs, became extinct
Adaptive radiation: Following the mass extinction, the surviving species experienced rapid diversification and evolutionary changes, leading to the rise of mammals and other new life forms

Study Guide

When studying the Cretaceous-Paleogene period, it's important to focus on the following key points:

The geological and biological events that occurred during the transition from the Cretaceous to the Paleogene
The causes and effects of the mass extinction event, including the role of volcanic activity and the Chicxulub impact
The concept of adaptive radiation and how it contributed to the diversification of surviving species
The significance of the K-Pg boundary in Earth's history and the subsequent changes in the planet's ecosystems

Further Exploration

For a deeper understanding of the Cretaceous-Paleogene period, consider researching specific fossil evidence, geological formations, and evolutionary trends that characterize this pivotal time in Earth's history.