Final answer:
The Cenozoic Era is known as the age of mammals and spans from 65 million years ago to the present. Mammals thrived in the niches left by dinosaurs, especially during the climate shifts of the Tertiary and Quaternary Periods, which also saw significant geological and vegetative changes.
Step-by-step explanation:
The Cenozoic Era: Major Changes and Developments
The Cenozoic Era, also known as the age of mammals, began roughly 65 million years ago after the mass extinction that marked the end of the Cretaceous period. This era is significant because mammals evolved to fill the ecological niches left vacant by the dinosaurs. During the Tertiary and Quaternary Periods, significant climate changes occurred. The Tertiary saw the development of modern ecosystems, with the evolution of grasses and coral reefs. In the Quaternary, a series of ice ages caused major extinctions and environmental shifts.
Mammals flourished during the Cenozoic Era, adapting to various climates and habitats. Some, like the woolly mammoths, evolved massive size and thick fur to survive the cold. The formation of land bridges due to lower sea levels during ice ages enabled land animals to migrate across continents.
Throughout the Cenozoic, Earth's geography and climate underwent dramatic changes that influenced geology and vegetation. These shifts also affected animal and plant life, leading to extinctions, migrations, and the rise of new species.