Dinosaurs are the extinct relatives of birds that roamed the lands and seas of ancient Earth. They first appeared around 240 ...

With a massive body, sharp teeth, and jaws so powerful they could crush a car, this famous carnivore dominated the forested river valleys in western North America during the late Cretaceous period ...

They began changing the way the world looked almost as soon as they appeared on Earth about 130 million years ago, during the Cretaceous period. That's relatively recent in geologic time ...

A known treasure trove of Early Cretaceous fossils has turned up a never-before-seen species of scorpion that lived around 125 million years ago. The venomous scorpion was larger than many ancient ...

They first appeared around 240 million to 230 million years ago in the Triassic Period, and went extinct around 66 million ...