This chapter explores the geography and ecology of the Cenozoic era. It cites how changes in continental positions have affected Earth's climates and the ability of vertebrates to disperse between its regions. By the late Mesozoic era, continental separation and epicontinental seas had isolated populations of terrestrial tetrapods and freshwater vertebrates, which limited possibilities for their migration between continents. While the best-known Cenozoic extinction took place at the end of the Pleistocene era, and this mainly affected only larger land animals. The chapter also considers debates on whether Pleistocene extinctions were mainly caused by climate changes or the spread of humans across the globe.
