India had detached from Africa and turned northwards toward several plates that were forming Asia. This began the process that raised the Himalayas. Antarctica had separated from Australia and drifted toward the South Pole, lowering temperatures worldwide. Australia became an isolated continent, producing its unique animals. First large terrestrial mammals, saber tooth tigers, horses, and marine mammals.
Mammals diversify and become very abundant.
Gastropods and bivalves thrive under the ocean. Most continents were near their present position. The North American continent experienced and uplift that raised the old Appalachian Mountains, and further lifted the Rockies. The Colorado Plateau also rose and the Colorado River began carving out the Grand Canyon. The friction of the westward movement of the continent as it overrode the Pacific Plate sprouted volcanoes from Alaska to Mexico.