The Mesozoic Era extinctions formed the world as we know it today. Read about what caused them and which animals survived.

The idea that extreme heat could one day cause a mass extinction and end the dominance of humans is not as farfetched as it ...

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

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

The so-called Cretaceous-Paleogene extinction (or K-Pg ... insurmountable barrier to survival. While this extinction ...

But the biggest development in the seas was the appearance of whales in the mid- to late Paleogene. The huge animals evolved from land mammals that took to the seas. Meanwhile, smaller reptiles ...

Along with sharks, many of these now-extinct species may have feasted on bottom-dwelling crustaceans ... layer of sediment or rock that geologists call the Cretaceous-Paleogene (K-Pg) boundary. The ...

Dire wolves went extinct roughly 13,000 years ago ... Here's a look at what we know about the prehistoric species: Along with saber-toothed cats and enormous short-faced bears, dire wolves ...

Mixodectes belonged to an extinct family known as mixodectids and lived during the Paleocene epoch. This geological epoch followed the Cretaceous-Paleogene extinction event that killed off non-avian ...