Cryogenian

The Cryogenian is a geological period that occurred between about 720 and 635 million years ago during the Neoproterozoic Era. It is notable for severe ice ages that possibly covered much of the Earth in ice, earning it the nickname "Snowball Earth." This extreme glaciation likely impacted the planet's climate and life forms. However, it also set the stage for the evolutionary burst known as the Ediacaran Period, which followed. The Cryogenian is important for understanding Earth’s climate history and the evolution of complex life.