4 Fossils

Fossils written by John Lockyer

Fossils are important signs of ancient life. They are found preserved in rock in many parts of the world. Fossils can be tiny plants and animals, or enormous dinosaur footprints and bones. Fossils are millions of years old.

A fossil can begin to form when an animal dies. Over a long time, the dead animal's body is covered with many layers of sand and mud. Then the sand, the mud, and the animal's bones slowly turn into hard rock. Sometimes, millions of years later, the fossil is uncovered.

body fossil Body fossils are the whole body or parts of the body of a plant or an animal. Imprint fossils are plants and trees that have rotted and left an imprint in rock. Trace fossils are markings, like footprints, tracks, burrows, and nests, made by ancient animals. sea shell fossils Fossils are found in strange places. Sea shell fossils have been discovered in the mountains. Scientists believe the mountains must have been under the sea long, long ago.

amber Body fossils have been found in amber. Amber is the hardened sap that comes from ancient trees. Tiny animals became fossils by being trapped in the tree sap, and then buried for millions of years. Many fossils are found in places with bare rock. Rocky shores, stream beds, caves, and sea cliffs have lots of fossils. These fossils are uncovered when water washes away part of the rocks.

Scientists work together to uncover a new fossil. Paleontologists decide what the fossil is. Geologists decide how old the rocks are. Technicians use small chisels, picks, and brushes to clean away rock, dirt, and dust from small fossils. Sometimes explosives and jack-hammers are used to uncover large fossils. If the paleontologists find enough bones, they can put the skeleton of the animal together. Any missing bones are replaced with plastic copies.