ASTEROIDS: Scientists have discovered a very large asteroid impact site in Antarctica.
Types of Fossils There are two main types of fossils: body fossils and trace fossils.
A body fossil is the physical remains of an animal. Some very small organisms, called microbacteria, leave behind microscopic particles called filaments.
Footprints, flowers, even droppings; all of these things can be turned into fossils under the right conditions.
A fossil only becomes a fossil when it has reached a certain age.
Dinosaur bones, on the other hand, are millions of years old -- some fossils are billions of years old.