Odrzucone teorie na temat wymarcia dinozaurów

Paleontologists are actively investigating what caused all nonavian dinosaurs to die out 65 million years ago. Most agree that the impact of a large asteroid or comet played a major role, while scientists continue to debate how volcanic activity or climate change caused by retreating sea levels might have contributed. Still, paleontologists can say for certain that some proposed explanations for the extinction of nonavian dinosaurs have proven false.

Get too big to survive? No. Most of the largest dinosaurs lived millions of years before the mass extinction.

Go extinct because their eggshells got too thin? No. Although some dinosaurs did have unusually thin eggshells, many others did not. Many survivors, including birds (living dinosaurs), crocodiles and turtles, all have thin eggshells.

Die out because mammals drove them to extinction? Did mammals eat all of the dinosaurs' eggs? No. Dinosaurs coexisted with mammals for over 150 million years, so there's no reason to think that mammals would have suddenly caused dinosaurs to go extinct.

Go extinct because their babies hatched as all males or all females? No. This theory—which is based on the fact that the sex of baby alligators and crocodiles is determined by outside temperature—can't be easily tested. But it cannot explain why other animals that rely on temperature-dependent sex determination survived.