The Eocene is a geological epoch that lasted from about 56 to 34 million years ago. It is part of the Paleogene period and is known for significant climate changes, including a warm climate that supported lush forests and diverse ecosystems. During this time, mammals began to diversify and evolve into many modern groups. The Eocene is also notable for the appearance of early forms of whales, horses, and primates. Fossil evidence from this epoch shows a rich variety of life, including the first true bats and the emergence of flowering plants, which became more widespread during this period.