You might know the Cretaceous Period for big animals such as Tyrannosaurus rex and Triceratops, or for being the end of the age of dinosaurs. But what was the world like in the millions of years ...

3 min read Continents were on the move in the Cretaceous, busy remodeling the ... and set in motion dramatic changes to the flora and fauna. An extraterrestrial impact or a bout of volcanism ...

Small fossils show mammals moved to the ground before the dinosaurs vanished. New plants changed habitats, giving better food ...

Researchers suggest that ground-based mammals fared better than their arboreal relatives during the end-Cretaceous extinction thanks to their lifestyle.

Many of these ancient animals were survivors of the Cretaceous-Tertiary extinction, though no one knows why they lived when so many others perished. Modern alligators are still closely related to ...

For months, scientists conclude, dense clouds of dust blocked the sun's rays, darkening and chilling Earth to deadly levels for most plants and, in turn, many animals. Then, when the dust finally ...