Tyrannosaurus Rex Tyrannosaurus rex arose during the Cretaceous period about 85 million years ago, and thrived as a top land ...

Opalized ammonite fossils are some of the most unique and spectacular paleontological specimens. They were formed through a ...

Earth once hosted more than 10,000 species of these ancient marine predators. Find out how they lived, when they vanished, and how much we know about them today. Based on the fossil record ...

Ammonites were shelled cephalopods that died out about 66 million years ago. Fossils of them are found all around the world, sometimes in very large concentrations. The often tightly wound shells of ...