A Brief Overview of the Miocene Epoch for Middle School Science Classes

Dec 17, 2024

3 min read

Earth history is a fascinating topic! It is also a massive topic! The reading passage below will teach you all about the Miocene epoch. If you want to learn more (and why wouldn't you?!), you can check out my Earth History page. I also have all of my passages available at Teachers Pay Teachers. They come with so many extras to get your students thinking about the content! I also recommend scrolling to the bottom of the page to check out my digital picture book on the Miocene epoch!

Miocene Epoch reading passage for middle school science

Less Recent

The Miocene epoch was the first epoch in the Neogene period. Miocene means “less recent.” Geologist Charles Lyell named the Miocene epoch because there were fewer modern animals during the Miocene epoch than the Pliocene epoch.

Climate

The climate of the Miocene epoch was warmer than the Oligocene epoch or the Pliocene epoch. However, the Earth was cooling.

Mid Miocene Climatic Optimum

Between eighteen and sixteen million years ago, the Earth suddenly warmed. Carbon dioxide levels jumped, leading to an increase in global temperatures and an increase in sea levels. Some of the extra carbon dioxide dissolved into the oceans, causing the water to become acidic. The carbon dioxide came from erupting volcanoes in the Pacific Northwest. You can see the basalt rock created by these eruptions today.

This abrupt increase in temperature has been named the Mid Miocene Climatic Optimum. Animals who could not adapt quickly enough to the environment went extinct. These extinctionsare called the Middle Miocene disruption.

Ice

Around eight million years ago, the temperature dramatically changed again. This time, temperatures dropped. For the first time, ice sheets formed on Greenland. The ice that formed on Antarctica at this time is still there today.

Mountains

The climate on Earth cooled because new mountains changed the air currents around the world. By the Miocene epoch, Africa had collided with Europe to form the Alps and India had collided with Asia to form the Himalayas. The Cascades and Andes were also rising.

Savannas and Kelp Forests

The cooling climate changed the vegetation on Earth. Tropical rainforests were replaced by grasslands. Savannas appeared for the first time on Earth. In the oceans, kelp, a type of brown algae, formed massive kelp forests.

Animals

These new environments caused animals to evolve. Animals that didn’t adapt to their surroundings went extinct, and animals that adapted well thrived. For example, deer, antelopes, and horses ate the new grasses and roamed the plains. Sea otters, fish, and other marine invertebrates lived and ate in the kelp forests.

Many modern mammals existed during the Miocene epoch. Dogs, bears, raccoons, beavers, camels, and whales looked similar to the way they look today. Animals were also on the move thanks to low sea levels and land bridges connecting the continents. Elephants and apes left Africa for Europe and Asia. Rabbits, pigs, and saber-toothed cats made their way to Africa. Horses traveled from North America to Europe, Asia, and Africa. Horses from North America would eventually evolve into the first zebras.

Apes

Apes were also evolving during this time. During the Miocene epoch, there were over one hundred species of apes living in Europe, Asia, and Africa. Around sixteen million years ago, orangutans split from the hominid line. The hominid line is the line that leads to modern humans. Around six million years ago, chimps split from the hominid line.

End of the Epoch

At the end of the Miocene epoch, the Earth was drying and cooling. This new climate and new environments led to the appearance of more modern animals. Modern animals would continue to evolve during the coming Pliocene epoch.

Miocene Epoch Picture Book

Looking for another way to learn about the Miocene epoch? Check out this picture book version. The pages are a part of my Earth History bundle on Teachers Pay Teachers.