How do shiny rocks get shiny? The answer is disgusting when it comes to dinosaur

© Dreamstime/TNS Some shiny round rocks are gastroliths, or gizzard stones from dinosaurs.

Turns out fossilized poop — called coprolites — isn't the only disgusting thing dinosaurs left behind for modern man to find lying around.

There are also gastroliths, an odd bit of the fossil record that is well disguised by natural beauty. "Often, we are shown pictures of shiny rocks and asked if they are gastroliths. But what is a gastrolith?" Dinosaur National Monument in Utah posted on Facebook.

"These are stomach stones or gizzard stones found in the digestive tract of animals that do not chew their food, like birds," the park wrote. "Some dinosaurs, like the long-necked sauropods, have been found with these gastroliths in their fossilized remains."

Park officials brought up the subject to help outdoorsy types figure out the difference between round rocks that are shiny — and shiny round rocks that are gastroliths...