Learn About Fossils

How Fossils are Formed

Learn how pieces of plants, insects, dinosaurs and other critters become fossils.


Learn about these ancient cephalopods: when they lived, where their fossils are found, their morphology and biology, and why some fossilized specimens still exhibit iridescence.

Knightia Fish Fossils

Learn more about this small freshwater herring from the Eocene Epoch, which is found in great numbers in the limestone strata of the Green River Formation in southwestern Wyoming.

Carcharodon megalodon: The "mega shark" of the Cenozoic Era

This fearsome apex predator of prehistoric oceans was the largest shark species known to marine paleontologists. Learn more about this amazing "megatoothed" shark.

Three Hidden Gems of the Fossil World

As a lover of fossils, I understand the appeal of the big and the bad—dinosaurs, sharks and lizards so large they can eat a man in one bite. But it isn’t the biggest and the baddest that make me giddy. There are a number of seemingly unremarkable fossils waiting for their “awesome-ness” to be discovered.

Petrified Wood and How It's Formed

How thousands of years can make a stone from a tree, and what we can learn from it.


Learn more about this ancient relative of the horseshoe crab, and why it is one of the most useful creatures in the fossil record.

Fossil Preparation

Learn more about how to prepare fossil specimens for display, from rough state to finished piece.

Ulrich's Fossils Tours and Gallery

If you're interested in fossils and planning a visit to Wyoming, Ulrich's quarry digs are exciting and rewarding. There is nothing that quite compares with the thrill of uncovering a 60 million year old fossil!

The Mystery of the Magnetic Dinosaur Bones

Learn how fossilized sauropod bones became magnetic, and how they provided a key to finding Seismosaurus fossils.

Columbian Mammoth, Mastodon Are Stars of Snowmass Fossil Site

Scientists are now settling in for a comprehensive study of an ancient treasure trove that promises to dramatically expand understanding of Ice Age fauna, flora and ecosystems in the Rocky Mountains.

Early Evolution of Carnivorous Dinosaurs Revealed in New Fossil Find

Tawa hallae, a previously unknown species of carnivorous dinosaur revealed recently in the journal Science, is providing new insight into the early evolution of dinosaurs.

Feathered Dinosaur Discovery: Older than Archaeopteryx

Anchiornis huxleyi, a new species of "profusely feathered" dinosaur discovered recently in northeastern China, is expected to give scientists new insight into the evolution of birds and flight.

Feathered Dinosaur Fossils Reveal Color Pigments

Recent investigations by a team of Yale University paleobiologists have revealed color pigmentation in the plumage of the oldest known feathered dinosaur, Anchiornis huxleyi.

Huge Dinosaur Tail, Believed to be Hadrosaur, Excavated in Mexico

Paleontologists in Mexico announced in July their excavation of a large fossilized dinosaur tail, which they believe belonged to a Hadrosaur. The find is significant, in part, because it is one of only a handful of intact specimens of this size to be discovered anywhere in the world.