Have you ever wondered how we know what dinosaurs looked like millions of years ago? We analyze fossils! When you think about dinosaur fossils, you might think about bones and footprints. But sometimes fossils contain pieces of skin. One example is the Psittacosaurus fossil located in a German museum. Many scientists examined the scaly skin of this specimen. We then re-examined this fossil using a technique called laser-stimulated fluorescence. This technique helped us gather information that was not visible under normal light. We found that the shape and size of the scales of the Psittacosaurus are not the same everywhere. We also learned that there are patterns in the scales. These patterns are unique to the family of dinosaurs to which the Psittacosaurus belongs.