The extinction of the dinosaurs represents the most famous of all the extinction events that have happened on the earth. For many, this event is perceived as a sudden downfall of the supreme ruling animal group. However there is strong evidence that the dinosaurs were on their way out anyway, and that the KT extinction was a final nail in their coffin. In the past 150 years numerous and often bizarre ideas have been suggested to explain why the dinosaurs died out 65 million years ago. As we do not have a time machine in which to travel back in time, to see what really happened, we have to rely on evidence from dinosaur remains and the rocks which contain them.
The situation is made more difficult as very few dinosaur remains are found, relative to the total number that lived. Therefore the basis for their extinction is the absence of any dinosaur remains in the Tertiary, rather than any positive evidence. Various researchers have made different interpretations on the rocks and bones, which has lead to the range of theories presented. Up until the 1950s their extinction was considered a minor event and of little interest. Then, in the 1950s they gained popular appeal, which resulted in a variety of theories for their disappearance being suggested. Many of these early suggestions lacked strong scientific evidence. From the 1970s onwards, there has been more of an attempt to provide realistic ideas, which do actually have some evidence to support them. While dinosaurs are of much interest and controversy today, there is still no one universally accepted theory for why the dinosaurs became extinct.
Most of the theories fall either into the gradualist or catastrophist approach. Long-term theories for the dinosaur extinction can be considered as gradualist in viewpoint, whilst sudden events, such as meteorite impacts are catastrophist in nature.
In an attempt to put the theories in some kind of order, they have put into those which are realistic theories, and others which are obviously joke suggestions. This page is intended to be a light hearted overview of the various theories.
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On to the possible theories
On to the less serious theories