Dawn Taylor, age 15, of Tulsa, Okla., for her question:
WHAT DOES THE PALEONTOLOGIST LEARN FROM FOSSILS?
By studying fossils, the paleontologist is able to learn what kind of life existed during various periods of the earth's history.
Paleontology is the science of the study of fossils. And fossils are the remains of plants and animals found in layers of sedimentary rocks. The animals and plants that are now fossils lived when the rocks were formed. They were buried and preserved as the layers of rock built up.
From fossils, the paleontologist has been able to tell us much about the earth's early days. The oldest fossils, for example, are one celled plants that lived at least 3 billion years ago.
By studying fossils, scientists have been able to discover a gradual increase in the complexity of animals and plants. This gradual change in body form is called evolution.
Geology also benefits from the study of paleontology. The ages of rocks may be determined by the fossils in them. Fossils also tell whether rocks were formed under the ocean or on land.
Most rocks that contain marine shell fossils were formed under the ocean while most rocks that contain land animals and land plant fossils were formed on land.
The knowledge of which rocks were formed under the ocean helps scientists map the world as it was millions of years ago. Such scientists are called paleogeographers.
Paleontology also gives assistance in finding the location of oil. Oil is often found in rocks that contain certain types of fossils. Oil companies use such fossils as clues in deciding where they will most likely find oil.
There are three main branches of paleontology: invertebrate paleontology which deals with fossil insects and shells, vertebrate paleontology and paleobotany.
Vertebrate paleontology is the branch of science that is concerned with extinct fishes, amphibians, reptiles, birds and mammals.
Paleobotany is the study of fossil plants.
From fossil remains, scientists have told us that about 600 million years ago animals developed hard skeletons and shells that have left good records of their existence in rocks.
Scientists measure the amount of certain chemicals in the fossils to tell how long the fossils have been in the earth.
Most dead plants and animals are eaten by animals or decayed by bacteria or fungi. Only those buried quickly and protected from decay can become fossils. Hard parts, such as wood, shells, bones and teeth, decay less easily than soft parts.