Preservation.(E) Preservation is an important word when studying fossils. (F) It means to keep something in the same condition for a long time. (G) One of the best examples of dinosaur fossils is in the Field Museum in Chicago. (H) The Tyrannosaurus Rex(or T-Rex) was the fiercest and largest dinosaur on the planet. It was a carnivore, or meat eater. T-Rex liked to eat smaller dinosaurs for dinner, using its powerful jaws to crush its victims. The skeleton of Sue was discovered in the dry plains of South Dakota in 1990 by Sue Henderson, a scientist. By studying prehistoric fossils, we can learn about life millions of years ago.