Cindy Levi, age 10, of Indianapolis, Indiana, for her question:

What does a paleontologist do?

A paleontologist studies fossils. And, since fossils are buried in the ground, he must do a lot of digging. Usually he starts by studying the solid ground far and wide. Often he can tell from the shapes and kinds of rocks where fossils are likely to be buried below. For example, limestone and sandstone rocks were built under the sea long ages ago. In layers of this sort he expects to find fossil shells that belonged to ancient sea creatures.

So a paleontologist must know a lot about the rocky earth and also when its different layers were formed. He also must know a lot about the fossils that already have been found. So when he finds one for himself, he can tell how old it is, what the world was like and what other plants and animals also lived in those bygone days. Some paleontologists are interested in the whereabouts of petroleum. For this buried oil is the fossil remains of creatures that lived long ages ago.