In the Age of New Imperialism that began in the 1870s, European states established vast empires mainly in Africa, but also in Asia and the Middle East. - https://www.tamaqua.k12.pa.us/cms/lib07/PA01000119/Centricity/Domain/119/TheAgeofImperialism.pdf
US, Germany, UK, and Russia
Here’s this hope this helps
The Cenozoic spans only about 65 million years, The Cenozoic is sometimes called the Age of Mammals, because the largest land animals have been mammals during that time.