ExTiNcTiOn+Of+DiNo'S++wOrK+cItEd

Nicole Sullivan Mrs. Crawford Connections-Section 1 23 March 2009 **__ Extinction of the Dinosaurs __** There are many explanations of how and why the dinosaurs went extinct. Today, I am going to try to tell you why that happened. When the dinosaurs went extinct, 44-46 million years ago, what ever killed them also killed 70% of all sorts of species. Lots of people think that a meteor or a comet killed them. That could be true, but only for some. If a comet did kill them it would only kill some- the ones in that particular area. Now, you see the problem. There had to be multiple reasons for the extinction to happen. The ones that lived in the water might have died because of a drop in sea-level. But what do we know….. nothing……yet. The oldest found dinosaur was found in a fossil that was traced back to 230 million years old. The name of the dinosaur was called Eoraptor. It was a small dinosaur that ate meat, but we don’t know if there are older ones or not. The past hides a lot of secrets. Lots of mysteries are still unsolved. Most of these mysteries are very interesting for people. Hopefully, this paper will solve the mystery of why the dinosaurs went extinct. I will examine new and old evidence to figure this out, but still I can’t be sure that they died of something, maybe they killed each other off. The dinosaurs went extinct around 44-46 million years ago. It could be more, it could be less, but lots of people think it was around that time. Most people think that the comet –if there ever was one- landed in the Yucatan peninsula, and people think it was after the comet landed, it was an after effect that killed them. At the end of the Cretaceous Period, all of the dinosaurs were gone. Researchers have found out multiple reasons for extinction. The most popular reason is a comet or meteor. Paleontologists show that a change in climate could be an answer. Another reason could be from poison grass due to a comet or meteor. Something as simple as a change in the Earth’s orbit may even have killed some. So this is still a pretty big mystery, but you can think what you want and you never know… you might be right. The theories that support the existence are that paleontologists have discovered many fossils of dinosaurs and there are approximately 700 species that they have named. We don’t know if there are more but people think there are anywhere between 700-900 more species. “These dinosaurs are grouped into 300 groups known as Stegosaurus, Diplodocus and many others. There is no written proof that something killed them. It may have been lots of things but there is not a 100% guarantee that a comet or even disease killed them. Maybe the thing that killed them, was little…maybe it was big, but we don’t know, and we may not ever. Some theories that go with the extinction are that the water level dropped because 70% of species also died. Another explanation is that climate changed which –sort of-- is a good explanation, because in Africa, where Egypt is now, that place was once all trees and plants and animals. Then it grew drier, and plants died because of the heat. Soon enough, all the animals ran away or died, because of the loss of food. The cooling period interrupted an extended warming out of an ice age predicted by slight changes in Earth's orbit (known as [|Milankovitch cycles] ) that continues today. And it remains an unexplained anomaly in the [|climate] record. These are three out of who knows how many reasons (or hypothesis’) the dinosaurs went extinct. The past hides a lot of secrets. Lots of mysteries are still unsolved. Most of these mysteries are very interesting for people. Now you can make up your mind, was it a comet, a drop in sea-level… we aren’t sure. But we do know that dinosaurs went extinct 44-46 million years ago, and there are about 700-900 species of dinosaurs. So think what you want, and you never know.