Fossils and Fossil Types
This term refers to the preserved evidence of an organism’s activity.
What is a trace fossil?
Only a small fraction of organisms become fossils, making the fossil record this.
What is incomplete?
This chart divides Earth's history into units such as eons and eras.
What is the geologic time scale?
This dating method determines the order of rock layers.
What is relative-age dating?
This occurs when the last individual of a species dies.
What is extinction?
An impression of an organism in rock forms this type of fossil.
What is a mold?
This process replaces original organic material with minerals.
What is mineralization?
The longest units of the geologic time scale.
What are eons?
This rock type is the best for absolute-age dating using radioactive isotopes.
What is igneous rock?
A change over time in populations of related organisms.
What is biological evolution?
This type of fossil forms when a mold is filled with minerals.
What is a cast?
After an organism dies, these hard parts most commonly remain.
What are bones and shells?
A rapid loss of many species defines this event.
What is a mass extinction?
Sedimentary layers stacked on top of each other allow scientists to determine this.
What is the relative age?
Fossils provide evidence for evolution because they show this over time.
What are related species changing?
This fossil type often shows movement or behavior such as footprints.
What is a trace fossil?
This environment best supports fossil formation.
What is muddy water?
Which event could cause extinction by blocking sunlight?
What is a meteor impact?
The exact age of a rock cannot be determined using this type of dating.
What is relative dating?
This event happens when many species die out in a short period.
What is a mass extinction?
Carbonization usually leaves behind this dark feature.
What is a dark outline?
Stromatolites are fossils created by these ancient life forms.
What are bacteria?
The record of all fossils ever discovered is called this.
What is the fossil record?
Scientists use these elements to find the absolute age of rocks.
What are radioactive isotopes?
Increased volcanic ash or dust can cause extinction by reducing this vital resource.
What is sunlight?