Paleocene

Paleocene.
The Paleocene is a geological epoch that started 66 million years ago with the Cretaceous–Paleogene extinction of non-avian dinosaurs and 75 percent of all species. The Paleocene was marked by the recovery of the biosphere, with dense forests worldwide, while small mammals and birds rapidly evolved to take advantage of the mass extinction. In the seas, ray-finned fish rose to dominance. The supercontinents Laurasia and Gondwana were still separating, the Rocky Mountains were being uplifted, the Americas were divided, the Indian Plate was colliding with Asia, and the North Atlantic Igneous Province was forming. Like the preceding Mesozoic, the Paleocene had a greenhouse climate, with an average global temperature of 24–25 °C (75–77 °F), compared to 14 °C (57 °F) today. It ended 56 million years ago with a sharp rise in temperature in the Paleocene–Eocene Thermal Maximum.