The+Devonian+Period+by+jtapta

__ The Devonian Period __

__How the Boston Harbor Islands Formed__ The thing that most drew me in to the Devonian period  Bibliography Reflection My Project  The Devonian period was a period of great importance. Though too was the period that preceded it, the Silurian, as ocean life began to flourish. But also the period that followed the Devonian, the Carboniferous, that was famous for it’s vast swamp forests. But not to be out-done, the Devonian period was //the age of fishes//, filled with surprises at every turn. There are many vital questions surrounding the abiotic of the Devonian period, but alas only the three most important can be answered. So first off, Where in the world was Massachusetts? Massachusetts was located on the southern coast of the super continent Euramerica, but more specifically, in the former micro-continent Avalonia. Next up, what is the latitude that covers most of the land? The land runs from about 60º north to about where the South Pole is. Now finally, what was the climate like? The Devonian was a relatively warm period, and probably lacked any glaciers. On average, the temperature was about 30º C (86º F) in the early Devonian. The mid-Devonian cooled off considerably to around 5º C (41º F) thanks in part to CO2 levels dropping steeply throughout the Devonian period as the burial of the newly evolved forests drew carbon out of the atmosphere into sediments. But the late Devonian warmed significantly to levels equivalent to the early Devonian. So while there was no corresponding increase in CO2 concentrations, continental temperature increased. Now you may be wondering, how in the world do scientists come to these great conclusions about the past of the planet Earth? Evidence my dear audience, evidence. By finding and discovering fossils of the undiscovered plants and animals, combined with the discovering of rocks from past landforms, the evidence for scientists can be unbreakable. So for fossils in the Devonian, there are three specific ones that I’d like to talk about. The first one is called the [|Rhynie Chert], which was a land plant from the early Devonian period, found in Scotland. The second is the Ichthyostega, a very well known amphibian found in Greenland. And the third and final one is the land dweller named Hynerpeton, found in Pennsylvania. As for the rocks and landforms, there were a few of those too. For example, today’s Scottish Highlands and the North American Appalachians are worn stumps of the Acadian-Caledonian Mountains. The “Devil’s Chimney” on the coast of Pembrokeshire, Whales, is an example of late [|Devonian sandstone]. Also because of the constant shifting of tectonic plates, a lot of “exotic terranes”, a.k.a. masses of old seafloor, volcanic island chains and chunks of continental material appeared quite a bit. So in conclusion, (no pun intended) to come to a conclusion, one first needs the evidence to back it up. The Devonian period was not just any old period, it was an age of vast life. It was //age of fishes//. But it wasn’t just fish. Living things on Earth were broken up in to two categories: multicellular and unicellular organisms. For multicellular, even though there were land plants in the Silurian period, they were relatively simple. The Devonian brought trees, Psilophyte plants and the of course none other than Rhynie Chert. But at the same time, new fish made splashes like Ammonoids, Eurypterids and also bony fish like Armored Placoderms. Up until the extinction of many of the fish species, many invertebrate arthropods and vertebrate fish ruled the Earth. But towards the end of the Devonian, over a ten million year span, the first amphibians had arrived. All that new land life must have attracted them. But now on to the unicellular. Bacteria and algae dominated pretty much all of the unicellular life. So not too exciting, but still cool. Fortunately though, so much of my project has been so unbelievably cool and interesting. I’ve learned things that I never could have imagined. Like the fact that once the Devonian period got going, for the first time plants got taller than three feet. Or like the fact that Boston was on the same continent as Europe. Now that’s pretty cool. It was amazing how things were in the great period of the Devonian. Here are some websites that I have have found very resourceful and I hope will help you all as well.
 * 1) [|The Devonian Period]
 * 2) [|The New York Times]
 * 3) [|Paleontology Portal - Devonian]
 * 4) [|The Devonian Times]