Fossils are remains of extinct organisms. Not all fossils come from dinosaurs, and not all dinosaurs (or parts of them) become fossilized. They may look like skeletons, but are actually rocks. Without fossils, we would likely never know that dinosaurs existed, and this wiki would not exist either! Fossils of dinosaurs are usually found in sedimentary rock, as igneous and metamorphic rock have been heated to very high temperatures, which destroys fossils. Sedimentary rock is built up of layers that represent different periods. This has provided evidence for the meteorite extinction theory, as the boundary between Cretaceous and Tertiary rocks contains huge amounts of iridium, a metal that is rare on earth but common in meteorites.
Many dinosaurs fossils have been found throughout the years. But some of the most famous are the fossils of Tyrannosaurus Rex. Some of the specimens are nearly complete, and change hands for several millions of pounds or dollars!
Another famous fossil is a Velociraptor and a Protoceratops, caught in battle, The Protoceratops is biting the Velociraptor's hand, and the Velociraptor's sickle claw is tearing at the Protoceratops' throat!
Are there just dinosaur fossils?
The answer to that question is no. Many fossils of extinct mammals and other animals have been found, such as the Mammoth and the Sabre Tooth Cat. But that's another story.