Khan Academy
Khan Academy: History of Life on Earth:biodiversity Flourishes in Phanerozoic Eon
Video lecture discusses Cambrian explosion and biodiversity in the Phanerozoic Eon. [10:27]
Khan Academy
Khan Academy: Introduction to the Geologic Time Chart
Did you know that Earth's 4.6 billion-year history has distinct periods? In this video, learn how geologists use evidence in rock record to classify these periods. [6:36]