Zach Holtslander & Steven Weber

Time Period The Devonian period took place during the Paleozoic era, and lasted from 416 to million years ago. It’s named for Devon, England, because that’s where Devonian period rocks were first studied. The Devonian period is split into 3 epochs: Early, Middle, and Late. The Early Devonian lasts from 416 to million years ago, and is made up of the Lockhovian, Pragian, and Emsian stages. The Middle Devonian lasts from to million years ago, and is made up of the Eifelian and Givetian stages. The Late Devonian lasts from to million years ago, and is made up of the Frasnian and Famennian stages.

Time Period Cont.

Landforms and Continent Positions The Devonian Period had lots of tectonic activity. Euramerica was formed by the collision of Laurentia and Baltica. Euramerica and Gondwana were starting to collide near the equator, which began the early stages of Pangaea. This raised the Appalachian Mountains, and formed the Caledonian Mountains. Much of the Earth was covered by one giant ocean called “Panthalassa”.

Landforms and Continent Positions Cont.

Animal and Plant Life Plants were abundant in the Devonian because of the warm climate. Life on land was good for plants because of the warm temperature. They developed the ability to carry food and water through the use of vascular tissues. Plants also developed the use of seeds during the Devonian. Because of that development, plants can now reproduce without being in the presence of water. Trees also began to cover the land. The bony fish, Osteichthyes, developed during the Middle Devonian.

Animal and Plant Life Cont. The plant covered land made a good home for the first wingless insects and spiders. The Devonian was the age of fish. Thousands of species of fish developed in this period. Most of the early fish fossils are of the Ostracoderms, because they were protected by scales and plates, as opposed to the cartilage that made up most other fish at the time. One fish that developed in the Devonian was the Dipterus, also called a “lungfish”, that could breathe out of water.

Animal and Plant Life Cont. The Coelocanth, a lobe-fin fish, developed during the Devonian. It was thought to be extinct, but a live one was caught in The Placoderms were the first fish to develop jaws, gills, and paired fins. The Devonian Period also saw the first sharks, which first appeared in the Middle Devonian. Obviously, they are still around today. Very little is known about the first sharks, because the cartilage they are composed of doesn’t fossilize well. Most of the information on early sharks comes from their fossilized teeth.

Animal and Plant Life Cont. A modern-day Coelacanth.

Climate and Atmosphere The climate during the Devonian Period was very warm, due to the continents being located near the equator. The sea levels were very high, which likely means there weren’t any glaciers during this period.

Mass Extinction The Devonian Period ended with a mass extinction, 364 million years ago. Palaeontologists believe the extinction was caused by global cooling. This cooling was triggered by a glaciation event on Gondwana. Water habitats were affected much more than land- based habitats. Sponges and corals were the most affected species. For thousands of years after the extinction, there was no major reef building.

References finds.com/devonian_period.html finds.com/devonian_period.html