Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025
Definition
The Cryogenian period is a geologic time frame that occurred approximately 720 to 635 million years ago, characterized by extensive glaciations. It played a crucial role in shaping the early evolution of multicellular life.
AP course connection
Topic 27.4: 27.4 The Evolutionary History of the Animal Kingdom