The Cenozoic Era was the Last era before the humans. It is home of the mammals and the great Ice Age. The plate boundary activity was crazy during this time. Areas of Earth were starting to break apart forming countries and the continents we have today. The climate changed during the different periods min this era. It started off tropical then went to drastic cooling causing the Ice age. The general types of species that survived during this time were birds, mammoths and other mammals. There were two mass extinctions during this time. The Eocene and Pleistocene. The Eocene was caused by a drop of climate change. It made marine life and plants become extinct. The Pleistocene was caused by a high climate change and human overkill. It caused all of the big animals like the mammoth and what not to become extinct. Species that disappeared because they could not adapt were mammoths and saber tooth tigers.