Final answer:
The Cenozoic is an era in the geologic time scale, known as the age of mammals, starting about 65 million years ago to the present.
Step-by-step explanation:
The term Cenozoic refers to an era within the geologic time scale. Specifically, the Cenozoic Era is known as the era of "modern life" or the age of mammals. This period began around 65 million years ago, after the extinction of the dinosaurs, and continues to the present day. Mammals evolved to fill the ecosystems left by the dinosaurs, leading to the rich biodiversity we see today. During the Cenozoic, there were significant climate changes, which included the ice ages in the Quaternary Period, the most recent of which ended approximately 12,000 years ago, marking the rise of Homo sapiens.