Cenozoic Era: 65.5 Million Years to Present
Paleogene Period: 65.5-23 Million Years Ago
The second largest mass extinction marks the end of the Mesozoic Era and the beginning of the Cenozoic Era. The Paleogene Period marks the beginning of the Cenozoic Era and extends from 65.5 to 23 million years ago. The Paleogene time Period is subdivided into the Paleocene, Eocene and Oligocene Epochs. Paleogene is derived from Greek and means "ancient birth". The Paleogene period is most notible for the adaptive radiations of mammals and birds following the extinction of non-avian dinosaurs. Both mammals and birds would evovle into essentially modern forms during the Paleogene. Use the drop down menu above or click on the pictures below to explore the epochs of the Paleogene.