Dinosaurs did not become extinct due to being generally maladapted or unable to cope with normal climatic change, a view found in many older textbooks. In fact, dinosaurs comprised an extremely adaptive and successful group, whose demise was brought about by an extraordinary event that also extinguished many groups of plants, mammals and marine life.]

The most commonly cited cause is that of an asteroid impact on the Yucatán Peninsula, triggering the Cretaceous - Paleogene extinction event. Also, not all dinosaurs went extinct. Birds evolved from small feathered theropods in the Jurassic, and while most dinosaur lineages were cut short at the end of the Cretaceous, some birds survived. Consequently, dinosaur descendants are part of the modern fauna.

Cultural depictions have also created or reinforced misconceptions about dinosaurs and other prehistoric animals, such as inaccurately and anachronistically portraying a sort of "prehistoric world" where many kinds of extinct animals (from the Permian animal Dimetrodon to mammoths and cavemen) lived together, and dinosaurs living lives of constant combat.

Other misconceptions reinforced by cultural depictions came from a scientific consensus that has now been overturned, such as the alternate usage of dinosaur to describe something that is maladapted or obsolete, or dinosaurs as slow and unintelligent.