The exact age of a rock. For example, "this rock is 300 million years old."
100
What is a paleontologist?
A scientist who studies fossils.
200
What do we call the empty space left in a rock by a dead organism that used to be there?
A mold.
200
What is relative age?
Relative age means we do not know the exact age of the rock, but we can compare it to the ages of other rocks. For example, "This rock is younger than the rock below it, but older than the rock above it."
200
What is an archaeologist?
A scientist who digs things out of the ground to study them.
300
What type of rocks are fossils normally found in? Why are they normally found in this type of rock?
Fossils are normally found in sedimentary rock because the fossils are covered by layers of sediment, which eventually hardens into rock.
300
The deeper the rock layer is, the ____________ it is.
Older
300
What is a cast?
A copy of a mold that is made by a scientist.
400
What is the fossil record?
All of the information that scientists can learn from studying fossils.
400
The closer to the surface a rock layer is, the __________ it is.
Younger
400
What is a petrified fossil?
An organism whose body, or part of its body, has turned to stone.
500
Give three examples of a trace fossil.
Footprints, nests, eggs, trails, coprolites.
500
What is the Law of Superposition?
The Law of Superposition says that rock layers form on top of each other. Therefore, the rocks layer on the bottom is the oldest, and the rock layer on top is the youngest.
500
What is an index fossil?
A fossil that can help us compare the ages of two or more rock layers.