When it comes to dinosaurs, teeth are the windows to these prehistoric reptiles' stomachs—and the different foods that filled them. Examine dinosaur choppers, strippers, grinders, and rippers.

When you've been alive for less than a decade, how in the world do you grasp geologic time? Start with a 100-inch-long roll of adding machine tape and measure out Earth's past.

What can you tell from looking at a fossil record of dinosaur footprints? Everything from which dinosaur was there first to what they might have feasted on.

Not all dinosaurs were enormous like the 84-foot-long, 30-ton Apatosaurus. TheCompsognathus, for example, approximated an eight-pound chicken. Size up two others.

The most common fossils are bones and teeth, but not all fossils are body parts. Explore the wide-ranging evidence of ancient life that scientists use to understand Earth's prehistoric past.

How many times would your footprint fit into that of a large dinosaur? Could all of your classmate's feet fill up the small crater? Find out with this personalized look at the 35-ton Apatosaur.

Dinosaurs all belong to the same group, but within that group there are many subsets—meat-eating dinosaurs, four-legged dinosaurs, and so on. Try your hand at classification with these eight dinosaur illustrations.

Some dinosaur names are short, while others are lengthy tongue twisters. But all are infused with meaning. Examine the linguistic roots of these terrible (deinos) lizards (sauros).