Explore an Era:
The Cenozoic is truly the Age of Mammals. At its beginning, the world is without any larger-sized terrestrial mammals. The next 65 million years brings marine mammals, such as whales and porpoises, as well as the land mammals, including Homo sapiens, that we know today.
After the Mesozoic's hot, tropical climate, the Cenozoic gave mammals a cooler atmosphere to evolve in. There was a gradual lowering of temperatures as well as the gradual establishment of different climatic zones--the tropics, the temperate zones and the cool climates of the higher latitudes.
The land masses and geography also take on their current shape during the Cenozoic. This separation of the great land masses allows biological evolution to take different paths in different parts of the world, creating a greater diversity of plant and animal forms.
During the last Ice Age, which occurs towards the end of the Cenozoic, the sea levels became much lower because so much water was converted to ice. This causes the creation of land bridges, such as the one across the Bering Sea, that connect the new continents and allow animal migrations.
The Cenozoic could also be called the "Age of Flowering Plants"--it is during this era that they become abundant. Mammals, of course, evolved to take advantage of this, using the fruits, berries and seeds for food.