How the dinosaurs became extinct

Science Coursework

In this piece of science coursework I will give evidence on several theories of how the dinosaurs became extinct.Dinosaurs suddenly became extinct approximately 65 million years ago. Many other groups of animals such as ammonites , mosasaurs, plesiosaurs, pterosaurs, herbivorous turtles and crocodiles, most birds, and many groups of mammals also became extinct at this time. This mass extinction is known as the Cretaceous–Tertiary extinction event. The nature of the event that caused this mass extinction has been extensively studied since the 1970s; several related theories are supported by palaeontologists. Though the general opinion is that an impact event was the primary cause of dinosaur extinction, some scientists believe other possible causes, or support the idea that a wide variety of factors was responsible for the sudden extinction of the dinosaurs.

Asteroid Theory

Probably the most popular theory right now is the Asteroid Theory. According to this theory a large asteroid or comet collided with Earth about 65 million years ago. Scientists think that such a large collision would throw so much dust into the air that sunlight would not be able to shine and plants and animals would die. The dramatic changes in climate that resulted from this huge collision were too much for the dinosaurs. They were not able to survive.

Volcanic Activity

Another theory that could explain how the dinosaurs became extinct is volcanic activity. ...

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Asteroid Theory

Another theory that could explain how the dinosaurs became extinct is volcanic activity. A huge increase in volcanic activity about 65 million years ago would have caused numerous volcanoes to erupt at once this would have pumped so much ash into the air that it would block out the sun killing off all the dinosaurs through the smog and dirt in the air or because they couldn’t get enough heat due to the sun being blocked out. The dinosaurs would have also been killed by the lava that came out of the volcanoes.

Ice Age

Some scientists believe that there was a severe ice age. Throughout Earth's history there have been many ice ages. The last one ended about 10,000 years ago. A very severe ice age could have changed temperatures and frozen a lot of Earth's water. If this did happen there would simply not be enough water for the dinosaurs to drink causing them to die out over a long period of time.

Disease

It has also been suggested that disease killed off the dinosaurs. A very deadly and contagious disease may have circulated among the dinosaurs all around the world causing them to become severely ill and eventually die.

Climate

Still yet another theory is that the Earth just gradually changed in climate over a long period of time and the dinosaurs were not able to adapt and change there lives to be able to survive on the changing world so they eventually died out.

Flowering Plants

Some scientists believe dinosaurs died out due to the rapid evolution of flowering plants. Many of the dinosaurs were herbivores causing them to eat such things as pine needles and evergreen trees. Then flowering plants appeared, replacing many of the pine trees. Dinosaurs did not have time to switch their diet to flowers and, as a result, died of starvation. Some dinosaurs lasted longer then others because some were carnivores eating other dinosaurs but they to would still die out because eventually the dinosaurs would become so few that the carnivorous dinosaurs would have nothing to eat also.

In conclusion there are many theories of how the dinosaurs became extinct many people believe different facts and opinions. I believe that the dinosaurs were made extinct by an asteroid colliding with the earth 65 million years ago I chose this theory because this seems to be the most realistic one to have really happened all those years ago and that’s what most scientists believe happened but nobody will never really know what happened to the dinosaurs all those years ago.

Peer Reviews

Here's what a star student thought of this essay

skatealexia

1st of Mar 2012

Quality of writing

The spelling is fine. The grammar is mostly okay, but sometimes sentence structure does not express the meaning of the sentence very clearly and sometimes the wrong words are used or words are missed out, also mixes up 'to' and 'too' and 'their' and 'there,' which are basic mistakes to make. The punctuation some work with commas being misplaced or missed out in some instances making the sentences harder to read. They follow the expectations of this level of work quite well although at the lower end of the spectrum. Uses the basic technical terms required at this level, and sets of the generic structure of the essay okay.

Level of analysis

Shows basic analytical skills for this level of qualification, but does not develop their ideas enough to show originality and their own thoughts on the matter throughout. Does not examine the validity of the different reasons for extinction of dinosaurs, just puts down different facts as a summary to what people believed at that time and the reasons for it. They seemed to have used appropriate scientific evidence although their sources are not quoted. The conclusion is not appropriate as it does not consider the validity of each of the opinions very well or analyse them. Also, the conclusion does not explain very well why they came to the conclusion they did.

Response to question

This essay outlines the different theories of extinction quite well, but there is no examination of the validity of each theory and how reliable the evidence for the different theories are enough to reach a good conclusion. Sets out the different theories of extinction in the introduction well enough, but the introduction could be made more concise and succinct. The main body of the text does examine the different theories of extinction of dinosaurs but does not answer the question of why dinosaurs became extinct very well as the main conclusion and analysis of these theories is quite poor. Their response is clear but not very well examined.

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