PlioceneMiocene

The Pliocene-Miocene is not a recognized geological epoch or period. It seems to be a portmanteau combining the Pliocene Epoch and the Miocene Epoch. These are distinct subdivisions of the Neogene Period within the Cenozoic Era.

The Miocene Epoch spans from approximately 23.03 to 5.333 million years ago. During this time, the Earth's climate was generally warmer than today, though it cooled over the course of the epoch. Continents were in positions that resemble their modern arrangements, and the formation of major mountain ranges like the Alps and the Himalayas continued. Life diversified, with the evolution of many modern mammal groups, including early hominins in Africa, as well as the expansion of grasslands.

Following the Miocene is the Pliocene Epoch, which lasted from about 5.333 to 2.588 million years ago. The cooling trend that began in the Miocene continued into the Pliocene, leading to the expansion of ice sheets at the poles. Seafloor spreading rates decreased, and ocean currents began to resemble those of the present day. Land bridges, such as the Isthmus of Panama, formed, allowing for the Great American Interchange, a significant migration of fauna between North and South America. Hominin evolution progressed, with genera like Australopithecus present.

Therefore, while the Miocene and Pliocene are sequential and important geological periods, they are distinct epochs and are not combined into a single entity known as "PlioceneMiocene."