The Online Library of Knowledge

How dinosaurs lived

Discovering dinosaur fossils

Fossil dinosaur bones at an excavation siteFossil dinosaur bones at an excavation site All we know about the dinosaurs has been gleaned from the study of their fossils. This science is called palaeontology. Much information can be gained—a dinosaur’s size, the way it moved, its diet—particularly when linked to knowledge of how modern animals live. Skin or feather impressions, footprints, eggs and dung are fossils, too, and provide further evidence about the dinosaurs’ lifestyles.

The fossilization processThe fossilization process

Fossil formation

Fossils form when a dead creature is quickly buried in sediment such as mud, sand or silt, for example, on a river bed or in the sea (1) The soft parts, including the internal organs, skin and muscle, usually quickly rot away, but minerals in the water fill up all the tiny spaces inside the hard parts that remain, such as shell, bones or teeth (2) Over millions of years, the layers of sediment build up and gradually compact into hard rock. The rock layers are often tilted or folded due to Earth movements (3). If that rock layer comes to the surface, perhaps as the result of erosion, the fossil may be revealed and discovered (4).

Not only body parts formed fossils. Signs of animals did too, like footprints made in soft mud by dinosaurs. The depth of the prints and the distance between them, tell us how fast a dinosaur walked or ran.

Palaeontologists often work in remote locations. They use a Global Positioning System (GPS) to record their exact location.

© 2019 Q-files Ltd. All rights reserved. Switch to Mobile