Dinosaurs

D. Finnin/© AMNH
Dinosaurs are a group of reptiles that first appeared about 245 million years ago.

They dominated the planet until an extinction event wiped out a large swath of life on Earth about 66 million years ago. But now we know that the Age of Dinosaurs never ended. Instead, a group of dinosaurs gave rise to a new, small airborne form: birds.

Extinction: What happened 65 million years ago?

The leading theory is that a huge asteroid or comet slammed into Earth 65 million years ago, blocking sunlight, changing the climate and setting off global wildfires.

What Happened? »
Rendering of a late-Cretaceous asteroid impact that may have led to the extinction of non-avian dinosaurs. © AMNH

Watch our extensive collection of dinosaur videos.

Dinosaur Basics

Article Dinosaur Names Find out how dinosaurs get their names and the meanings of their Greek and Latin roots. Article Types of Dinosaurs Learn how many species have been discovered, and see photos and information about over 40 types of dinosaurs.
Article Dinosaur Bones Discover what scientists can learn by studying fossils and how these fossils are stored in the Museum’s collections. Article Dinosaur Eggs Fossilized eggs have helped scientists understand how dinosaurs reproduced and cared for their young.
Educator Materials Dinosaurs: Activities and Lesson Plans Resources to help students understand everything from basic dinosaur biology and evolution, to the tools and methods of modern paleontology. Reading Ask a Scientist About Dinosaurs Paleontologist Mark Norell answers kids’ questions. Article The Dinosaurs on Display Plan your visit to see the Museum's dinosaurs, part of the largest collection of fossils in the world. Article Tyrannosaurus rex Seven questions about T. rex answered! Article Dinosaurs Survive! Not all dinosaurs died out 65 million years ago. Collection Dinosaur Discoveries The 21st century is shaping up as a great time to be a paleontologist: here's the latest in our understanding of dinosaurs. Exhibit The Titanosaur This cast is of a 122-foot-long dinosaur that lived in forests of today’s Patagonia about 100 to 95 million years ago.