Dinosaur Hunters

Dinosaur Hunters

Secrets in Stone Jim Jensen was a famous dinosaur hunter. He discovered a meat-eater that no one had ever seen before. He also found a giant dinosaur. He called it Supersaurus(SOO-pur-SAW-rus)，or “ super lizard. ” Jim Jensen was one of the best dinosaur hunters of his time. That's how he got the nickname “ Dinosaur Jim. ” Of course dinosaurs don't live on earth today. The last ones disappeared about 65 mil- lion years ago. So how could Dinosaur Jim hunt dinosaurs if there weren't any around?

To find out, imagine the earth 150 million years ago. Many seas are warm and shallow. The ground is covered with mosses and ferns. There are many tall trees with fan-shaped leaves. Dinosaurs of all shapes and sizes roam the earth.

Some of the dinosaurs are the size of a chicken. Other dinosaurs are as tall as a four-story building. Some have scales and tail spikes. Some have feathers. There are no people yet. It is the middle of the Mesozoic (MES-uh- ZO-ick) Era. It is the Age of Dinosaurs.

Picture a gigantic Apatosaurus (ah-PAT- uh-SAW-rus) walking on a riverbank. This Apatosaurus is old and weak. It bends its long neck and takes one last drink from the river. Then it falls on its side in the mud. It is dead. Most of the soft flesh of the Apatosaurus is quickly eaten by animals. The rest rots away. In time, the hard bones sink into the mud. The mud protects the bones. They do not rot away. For millions of years, the bones lie under the ground. Rain falls. It seeps down through the ground, dissolving minerals in the rocks. The rainwater carries these minerals along as it trickles down to the bones. Like all bones, the Apatosaurus bones are filled with tiny holes. The rainwater seeps into these holes. The water evaporates. But the min- erals in the water stay and harden in the bones. Little by little, what once was bone turns to stone. The bones of the Apatosaurus are now stone. They are fossils.