Fossils of dinosaurs have now been found on every continent, almost everywhere that rocks of Late Triassic, Jurassic, or Cretaceous rocks are exposed on the Earth's surface. Because dinosaurs were (and in the form of birds still are) such a diverse group or animals, they probably lived in nearly every terrestrial environment. Their fossils, whether bones, teeth, or footprints, have been found in Mesozoic rocks that are geologically interpreted to have been deposited in deserts, savannahs, forests, beaches, and swamps.