What geological period provides the setting for the original film Ice Age?

The original film Ice Age is set during the Pleistocene.

The Pleistocene was a geological epoch that lasted from about 2.58 million years ago until roughly 11,700 years ago. It is commonly associated with repeated glacial and interglacial periods, as well as large Ice Age mammals such as woolly mammoths and saber-toothed cats.

Ice Age uses this prehistoric setting as the backdrop for its fictional migration story. Manny is a woolly mammoth, Diego is a saber-toothed cat, and Sid is a ground sloth, although their conversations and social behavior are deliberately modern and comedic.

The Pleistocene should not be confused with the Holocene, the geological epoch that followed it. The Jurassic and Cretaceous are much older periods, best known for different dinosaur-dominated ecosystems.