Formation

• Most of the information we know, or guess, about dinosaurs comes from fossils.

• Fossils are the remains of once-living things that have been preserved in rocks and turned to stone, usually over millions of years.

• Not just dinosaurs, but many kinds of living things from prehistoric times have left fossils, including mammals, birds, lizards, fish, insects, and plants such as ferns and trees.

• The flesh, guts, and other soft parts of a dead dinosaur's body were probably eaten by scavengers, or rotted away, and so rarely formed fossils.

• Fossils usually formed when a dinosaur's remains were quickly covered by sediments such as sand, silt, or mud, especially along the banks of a river or lake, or on the seashore.

• The sand or other sediment around a creature or plant's remains was gradually buried deeper by more sediment, squeezed under pressure, and cemented together into a solid mass of rock.

• As the sediment turned to rock, so did the plant or animal remains encased within it.

• Information about dinosaurs comes not only from fossils, but also from "trace" fossils. These were not actual parts of their bodies, but other items or signs of their presence.

• Trace fossils include egg shells, footprints, marks made by claws and teeth, and coprolites--fossilized dinosaur droppings.

STAR FACT By: Parker, Steve, Dinosaurs
The hard parts of a dinosaur's body were the most likely parts to form fossils, especially teeth, bones, claws, and horns.

By: Parker, Steve, Dinosaurs