Renee' Marie Basso, age 10, of Richmond, Virginia, for her question:

How did the Jurassic Period get its name?

The geological eras are named for phases in the story of life. Many of the geologi¬cal periods are named for places where ancient fossils and rock formations were dis¬covered. The Mesozoic or Middle Era spanned more than 100 million years. The Jurassic Period is a central chapter in this era that began about 155 million years ago and lasted through some 25 million years. The rocky formations and fossils of this period first were noticed in the Jura Mountains of Central Europe. This lofty range of ragged peaks forms a natural borderline between France and Switzerland.

In the last century, earth science was rather new. Scholars were just beginning to believe that the earth has a long and eventful past. The evidence was shown in the mountains and rocks of the crust and also in ancient fossils. The rocky peaks and jumbled layers showed just how and when the Jura Mountains were formed. So this geo¬logical phase was named the Jurassic Period. Later, events that happened at this same time were unearthed in other parts of the world and included in the story of the Jurassic Period.