The reason behind the demise of the dinosaurs has long fascinated both the scientific and non-scientific community. Why did such a successful group of organisms suddenly fall victim to extinction and perish?
Since the late eighteenth century, scientists have been trying to determine the nature of the extinction process, not only those that killed off the dinosaurs, but also those which caused the disappearance of numerous other groups that preceded and followed the dinosaurs. Sudden extinctions (confined to a few million years or less) which sweep away a large variety of living creatures are termed by paleontologists as mass extinctions (Steven Stanley, 1985).

Paleontologists divide geological history into several periods, extending from the Precambrian to the Quaternary. As indicated on the geological time scale to the right several mass extinctions have occurred throughout earth history (boundaries of each geological period are given in millions of years).

Click here to view Mass Extinctions of Earth History

Click here to view Mass Extinctions of the Phanerozoic

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