👉 The term "cenozoic" refers to the era of life that began around 250 million years ago, during which a significant portion of Earth's history is considered. This period marks the transition from the Paleogene (around 348-166 Ma) to the Cretaceous (around 69-76 Ma). The Cenozoic era was marked by the extinction of many species and the emergence of new ones, including the dinosaurs.