When did the Cenozoic Era begin?

The Cenozoic Era began about 65 million years ago and continues today. It is the third documented era in the history of the Earth. It is marked by the proliferation of mammals, birds, grasses and flowering plants.

The Cenozoic Era follows the Cretaceous Era, which ended with the extinction of the remaining non-avian dinosaurs. The Cenozoic Era is divided into three parts: the Paleogene Period (65-23 million years ago), the Neogene Period (23-2.6 million years ago) and the Quaternary Period (2.6 million years ago to the present). The term "Cenozoic" is derived from a Greek phrase that means "recent life."