Dinosaur Extinction Research Paper

Sixty-five million years ago the dinosaurs died out along with more than 50% of other life forms on the planet. This mass extinction is so dramatic that for many years it was used to mark the boundary between the Cretaceous Period, when the last dinosaurs lived, and the Tertiary Period, when no dinosaurs remained. This is called the Cretaceous/Tertiary (or K/T) boundary, and the associated extinction is often termed the K/T extinction event.The name "Tertiary" is a holdover from the early days of geology, and many geologists now prefer the term "Paleogene" for the time period that immediately follows the Cretaceous. These scientists refer to the Cretaceous/Paleogene or K/P boundary, which represents the same moment in time as the K/T event. Since their discovery in the nineteenth century, the reason for the dinosaurs' demise has been a matter of speculation and debate. Early paleontologists, working prior to Darwin's theory of evolution by natural selection, suggested that

Most theories focused on climate change, perhaps brought on by volcanism, lowering sea level, and shifting continents. But hundreds of other theories were developed, some reasonable but others rather far-fetched (including decimation by visiting aliens, widespread dinosaur "wars", and "paläoweltschmertz"­the idea that dinosaurs just got tired and went extinct). It was often popularly thought that the evolving mammals simply ate enough of the dinosaurs' eggs to drive them to extinction.

Regardless of the details, most of these theories shared the common thought that dinosaurs were a group of animals that had reached the end of their evolutionary life. Their extinction was seen as inevitable, the product of having evolved for too long. In most extinction scenarios, the dinosaurs were simply unable to cope with competition from mammals and the changing climate, and so they all went