Eoseenikauden

Eoseenikauden, often referred to as the Eocene epoch, is a geological period that spans from approximately 56 million to 33.9 million years ago. It is the second epoch of the Paleogene Period, following the Paleocene and preceding the Oligocene. The Eocene was a time of significant climatic and biological change following the K-Pg extinction event that wiped out the non-avian dinosaurs.

Globally, the Eocene was characterized by a much warmer climate than today. Average temperatures were considerably higher, and there was a significant reduction in ice cover, with polar regions being largely ice-free. This warmth facilitated the widespread distribution of diverse flora and fauna, including the establishment of lush forests in areas that are now temperate or even polar.

During the Eocene, mammals diversified and evolved rapidly, filling the ecological niches vacated by the extinct reptiles. This era saw the emergence of many modern mammal groups, including the earliest ancestors of primates, whales, bats, and ungulates (hoofed mammals). Early forms of horses, elephants, and rhinos also appeared. The oceans teemed with marine life, including various species of sharks, bony fishes, and early whales.

The Eocene concluded with a significant cooling event, the Eocene-Oligocene extinction event, which led to a decrease in global temperatures and the formation of the Antarctic ice sheet. This climatic shift marked the transition into the cooler Oligocene epoch and further reshaped the evolutionary trajectory of life on Earth.