Geology

Birds are - quite literally - living dinosaurs. Our quiz will test your knowledge of the fluffy, downy and winged dinos of the bygone Mesozoic era, from little Microraptor to the enormous Yutyrannus.

By Mark Mancini

To honor their prehistoric pasts, most U.S. states have designated official state fossils, ranging from trilobites to dinosaurs. Take our quiz to learn more!

By Mark Mancini

Decades after the massive conflict, reminders of battles linger in pristine Pacific waters.

By Christopher Hassiotis

Decades of fossil discoveries have revealed much about the extinct members of our hominid family tree, but we're far from having all the answers. What have we learned from some of these fascinating finds?

By Jane McGrath

The world of our far-future descendants may be as unrecognizable to us as our bustling, urbanized world would be to our bewildered ancient forefathers. Will energy drive many of those changes?

By Robert Lamb

The Doll's Theater of Carlsbad Caverns looks otherworldly and took ages to form. What other incredible sights await us below ground?

By Julia Layton

Diamonds are some of the most brilliant and expensive natural features Earth has to offer. This collection of images displays diamonds in all their uncut and polished shapes and sizes. Obligatory pictures of very large diamonds are included of course.

By HowStuffWorks.com Contributors

One grows from the ground and one from the ceiling, but sometime's it's hard to remember which is the stalactite and which is the stalagmite. How do they get there, anyway?

By John Fuller

The 1993 movie "Jurassic Park" did a good job of bringing the idea of cloning dinosaurs into popular culture. It portrayed dinosaur cloning in a way that made sense to a lot of people, but is it really possible?

By Tracy V. Wilson

Every time a new fossil is found, one of the first things scientists determine is how old that fossil really is. But how do they determine it, and how can they be completely accurate?

By Tracy V. Wilson

Saber-tooth cats have long been likened to tigers, but they aren't tigers at all. While they share some physical traits and hunting practices with tigers, saber-tooth cats are also quite different.

By Tracy V. Wilson

Earthquakes and volcanoes get all the press. But the landslides they trigger are often more devastating. What makes the ground suddenly rip downhill, taking trees and homes with it?

By Jennifer Horton & Mark Mancini

It's not a trick; before you are a number of reptilian footprints in the rock. They're dinosaur tracks, preserved for thousands of years. But how did they possibly get there?

By Tracy V. Wilson

Some people believe that dinosaurs were relatives of today's birds. But, you might ask, if that's so, why didn't they have feathers? Funny you should ask.

By Tracy V. Wilson

We all know the cartoons of prehistoric people running from dinosaurs aren't realistic. But many animals living today have ancestors from that time.

By Tracy V. Wilson

Sand dunes belch, moan and hum. They roll across the desert, seeking out new locales. You might even say they breed. It's no wonder people call these giant sand formations lifelike.

By Debra Ronca

Researchers think the Chicxulub crater was caused by the massive asteroid that also killed off the dinosaurs 66 million years ago. What else do we know about this peak-ring crater?

By Mark Mancini

Anthropologists specialize in, well, us. But studying humankind doesn't mean you have to hole up in a library or laboratory. Take a peek at this article to learn more about the dynamic, enriching field of anthropology.

By Nathan Chandler

When it comes to fossils, specimens like Sue the Tyrannosaurus rex grab much of the attention. And while Sue is a staggering 67 million years old, she's a new kid on the block, compared to some of the oldest fossils ever found. What's older than Sue?

By Jonathan Atteberry

Sometimes dinosaur fossils are too large and heavy to display without damaging them. How are those enormous models built? And what makes them look so realistic?

By Tracy V. Wilson

Did you know that sand dunes can sing? And, their artistic curves certainly make for a gorgeous photograph. In fact, you might call the sand dune the diva of the desert.

By Debra Ronca

Carbon-14 dating is something that you hear about in the news all the time. Everything from mastodons to the Shroud of Turin has been dated using this technique! Learn about how carbon-14 dating works and why it is so accurate!

By Marshall Brain

Diamonds are beautiful and popular - but not everyone can afford these gems. While man-made versions are less expensive, most lack the luster and brilliance of the real thing, except moissanite. See how it compares!

By Melissa Russell-Ausley

Diamond engagement rings. Diamond anniversary bands. Diamond earrings and necklaces. And now, the right-hand diamond ring! The four Cs -- cut, clarity, carat and color. Find out what the fuss is all about.

By Kevin Bonsor

Countless movies and television shows depict quicksand as some kind of living creature that sucks its victims down into a bottomless pit, never to be heard from again. Well, you can't believe everything Hollywood tells you.

By Kevin Bonsor