digging up the past SOUTH DAKOTA PRAIRIE The summer sun beats down on South Dakota’s endless prairie The flat land is covered with tall grasses A group of paleontologists carefully chips away at a rock After hours of work a fossil begins to emerge
PALEONTOLOGISTS FERN IMPRESSION Other fossils are found nearby The impression of a large leaf seems out of place in this treeless landscape Thousands of years ago this prairie was a lush jungle crawling with dinosaurs
what are fossils Fossils are the preserved remains of ancient organisms Fossils are at least 10,000 years old Some are more than 3 billion years old Paleontologists study fossils to understand ancient life They dig up fossils from rock layers In most cases fossils are not the actual bodies of organisms Instead they are rocks or cavities left in rock Soft materials such as hair do not preserve well Hard materials like bones make better fossils CAVITY FOSSIL
