A Brief Overview of the Devonian Period for Middle School Science Classes

Dec 14, 2024

2 min read

Earth history is a fascinating topic! It is also a massive topic! The reading passage below will teach you all about the Devonian Period. 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 Devonian Period!

Naming the Period

Adam Sedgwick and Roderick Murchison named the Devonian period after Devon, England. They had been studying the red rocks of the area when they discovered a new species of graptolite fossil. They named the Devonian period in 1839.

Continents

The red rocks of Devon had formed when North America crashed into Europe during the Silurian period. This formed the continent Laurussia. Meanwhile, Gondwana, which had been at the South Pole, began to move north. The tectonic plate under Gondwana was subducting under Laurussia’s plate. Millions of years after the Devonian period ended, the two continents formed the supercontinent Pangaea.

Climate

The climate was warm during the Devonian period. A giant ocean covered 85 percent of the Earth. Most life existed in the shallow waters along the coasts of the continents. Scientists aren’t sure why, but oxygen levels in these waters were low. This lack of oxygen caused many extinctions. Some animals were able to adapt to this change by growing lungs. With lungs, these animals were prepared to move to land.

Land Plants

Plants on land continued to evolve during the Devonian period. Lycophytes, horsetails, and ferns became the first vascular plants on land. Vascular tissues carry water and food throughout the plant. The first trees also appeared during the Devonian period. Archaeopteris was one of the first trees. It was similar to a conifer tree. It had no leaves but did have fern-like branches. It was most likely deciduous because it lost its branches once a year. These trees could grow up to one hundred feet tall. Plants and trees were able to move away from the water because of seeds. Seeds allowed the plants to reproduce without water. These new plants and trees formed the first forests on Earth.

Ocean Life

Corals and sponges continued creating massive reefs in the coastal waters. These reefs created habitats for brachiopods, trilobites, and other invertebrates. Invertebrates are animals without backbones. Ammonites first appeared in the oceans during this time. They make great fossils because of their spiral shells. Eurypterids, or sea scorpions, were an important predator of the Devonian period, but fish dominated the food chain. This is why the Devonian period is called the "age of fish."

Devonian Period Picture Book

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