Devonian Period

• https://samnoblemuseum.ou.edu/understanding-extinction/mass-extinctions/late-devonian-extinctions/
• https://ucmp.berkeley.edu/devonian/devonian.php#:~:text=The%20first%20tetrapods%20%E2%80%94%20land%2Dliving,and%20ammonites%20were%20also%20common.
• https://www.nps.gov/articles/000/devonian-period.htm
• https://ucf-flvc.primo.exlibrisgroup.com/permalink/01FALSC_UCF/1mkl1r8/alma99383218498606596
• https://ucf-flvc.primo.exlibrisgroup.com/permalink/01FALSC_UCF/1mkl1r8/alma990336519060306596

References

Fun Facts!

The greatest mass extinction event during this period is referred to as the end-Fransian extinction, which occured about 375 million years ago. Although this was not towards the end of the period, this one had the greatest effect on the marine life. Many of the corals and reefs became extinct and disappeared altogether due to climate change. This can be traced back to the large forests that formed. The larger the plants were getting, the more carbon dioxide that was being taken during photosynthesis. This lowered the amount that was found in the atmosphere, cooling the planet. Additionally, as these plants and trees were depleating, many of them were consumed by the water, meaning the carbon dioxide did not have the chance to return back to the atmosphere.

Mass Extinction Event

419.2 - 358.9 Million Years Ago

Devonian Period

The Devonian Period is often referred to as the "Age of Fishes" due to the greatest changes with marine animals. During this period, we can see the introduction of the first fish, some relating closely to sharks and some having no jaws, which are the ancestors to many of the common fish we see today, like tuna, salmon,etc.,. In addition to this, the first tetrapods appeared because of the low oxygen levels that caused shallower waters and the ability to find other resources, like food, on land. The ability to sustain themselves on land allowed for the adaptation to breathe air and devlop limbs.

Although the Devonian Period saw many changes in animals, there was also a great advancement in the landscape. Leading up to this period, the soil was reddish in color due to the fact that it was home to primarily bacteria and algea; However, early vegatation had started appearing. This land was in two supercontinents, while the rest of the planet had remained ocean. In these oceans, coral and reefs started increasing, forming some of the largest complexes.

Although not as we know today, the beginning of the period saw new vegetation start growing. These new plants had no roots or leaves, but still spread throughout the land. They did not grow tall and were no more than a few centimeters tall. However, these plants were still home to various animals, including wingless insects. Towards the end of this period, however, these plants flourished, now growing tall and showing roots and leaves. This allowed for the diversification of athropods as these plants now had seeds and were able to stay in the soil and transport water and food through their stems.

• During the formation of the supercontinents, they collided which resulted in the initial rise of what we know now know as the Appalachain moutains
• This period saw a total of 3 mass extinction events, although the Fransian produced the most significant impact, being considered part of the "Big Five."
• Over the course of the extinctions 70 - 80% of marine life disappeared.
• The largest living animal during this period was the Dunkleosteus, which was a predatory fish that grew up to 33 feet long.
• The Devonian period was named after Devon, South West England as this was the location where rocks from this period were first studied.
• A year during the Devonian period was roughly about 400 days, which means that days would last 22 hours long.