The Miocene Epoch

During the Miocene period earth’s climate, had changed from cold to warm with steamy jungles and searing deserts. By the end of the Miocene epoch the ancestors of humans had split away from their ancestors of chimpanzees to follow their own evolutionary paths. In the Miocene seas, kelp forests made their first appearance and soon became part of the Earth’s most productive ecosystems.

The Miocene epoch began 23.8 million years ago, and ended 5.3 million years ago. Many plants and animals flourished during the Miocene period as climate and weather was perfect for life. Some animals that were flourishing during this period were Teuthidas, Cervidae, Elephantidae, Felidae, Canidae, Accipitridae, Corvidae, Crocodyidae, Boidae, and Salmonidae. Some plants that were flourishing include Orchidaceae, Poaceae, Pinophyta, Fagaceae, Pinales, Liliaceae, and Rosaceae. During the Miocene period, life was mostly supported by two newly formed biomes, Kelp forests and Grasslands. Grasslands allowed for more grazers such as Horses, Deer, Rhinos, and Hippos. Ninety-five percent of modern plants existed by the end of this period.

The Miocene period was a time of warmer global climates than those in the preceding Oligocene. The Miocene warming began 21 million years ago, and continued until 14 million years ago. By 8 million years ago, temperatures dropped sharply once again, and the Atlantic ice sheet was already approaching its present-day size and thickness. Greenland may have begun to have large glaciers as early as 7 to 8 million years ago, although the climate for the most part remained warm enough to support forests.

The pattern of biological change for the Miocene is one of the expanding open vegetation systems such as tundra, deserts, and grasslands, at the expense of diminishing close vegetation such as forests. This led to the re-diversitation of temperate ecosystems and many morphological changes in animals. Mammals and birds in particular developed new forms, whether as fast-running herbivores, large predatory mammals and birds, or small quick birds and rodents. Because the Miocene is closer to the present day than most other periods of geologic time, it is easier to see the effects of events, and to interpret patterns. Many of the fossil species of this time have close relatives alive today, which can be good and bad.

During the Miocene period continents continued to drift toward their present positions, of the modern geologic features only the land bridge between South America and North America was absent. Although, South America was approaching the Western subduction zone in the Pacific Ocean causing both the rising of the Andes mountains and a southward extension of the Mesoamerican peninsula. Mountain building took place in Western Europe, East Asia, and North America. India continued to collide with Asia, creating new mountain ranges. The subsequent uplift of mountains in the western Mediterranean region and a global fall in sea levels combined to cause a temporary drying up of the Mediterranean Sea known as the “Messinian salinity crisis”. The global trend was towards increasing aridity caused primarily by global cooling, reducing the ability of the atmosphere to absorb moisture. Uplift of East Africa in the late Miocene period was partly responsible for the shrinking of the tropical rainforests in that region, and Australia got drier as it entered a zone of low rainfall in the late Miocene period.

The Miocene epoch was a very good period for life on earth as weather and climate were very suitable for life.