The Cenozoic or Cainozoicera (sometimes Caenozoic Era) is the most recent of the four classic geological eras. It covers the 64 million years since the extinction event at the end of the Cretaceous that marked the demise of the last dinosaurs and the end of the Mesozoic Era. The Cenozoic era is still ongoing.
The Cenozoic is the age of mammals. During the Cenozoic, mammals diverged from a few small, simple, generalized forms into a diverse collection of terrestrial, marine, and flying animals. Flowering plants and birds also evolved substantially in the Cenozoic.