Eocén

The Eocene epoch is a geological epoch that lasted from about 56 to 33.9 million years ago. It is the second epoch of the Paleogene Period and followed the Paleocene epoch. The Eocene was a time of significant warming and diversification of life, particularly mammals.

The early Eocene was characterized by a global warming event known as the Paleocene-Eocene Thermal Maximum (PETM), which caused rapid temperature increases and sea-level rise. This event had a profound impact on ecosystems, leading to extinctions and the migration of many species. Following the PETM, temperatures gradually cooled throughout the Eocene.

During the Eocene, the Earth's climate was generally warmer than today, with no permanent ice caps at the poles. Tropical and subtropical forests extended to high latitudes. The continents continued to drift towards their present positions. Africa collided with Eurasia, closing the Tethys Sea and forming the Alps. The Atlantic Ocean continued to widen.

The Eocene saw the explosive diversification of mammals. Following the extinction of the non-avian dinosaurs at the end of the Cretaceous, mammals began to evolve into a wide array of forms, filling newly available ecological niches. Major groups of modern mammals, including primates, rodents, bats, whales, and ungulates (hoofed mammals), appeared and diversified during this epoch. Birds also underwent significant evolutionary radiation.

Plant life also changed. Forests dominated most landmasses, with flowering plants becoming increasingly widespread. The cooling trend in the latter half of the Eocene contributed to the expansion of more temperate forests.

The Eocene ended with another significant global cooling event, the Eocene-Oligocene Transition, which led to the formation of the Antarctic ice sheet and major changes in marine and terrestrial life.