History of Planet Earth

Front

What is a key bed?

Back

A layer of rock that scientists use to determine the time period in which it was formed.

Front

What is the most common type of fossil?

Back

Trace fossil.

Front

Which period is the most recent?

Back

Cretaceous period.

Front

What does 'sample' mean in scientific terms?

Back

A small amount of material used for observation.

Front

What type of rock do most fossils come from?

Back

Sedimentary rock.

Front

What is sedimentary rock?

Back

A type of rock formed by the accumulation of sediments.

Front

What is an index fossil?

Back

A fossil that is used to define and identify a particular time period.

Front

What is a mold fossil?

Back

A fossil that forms when an organism leaves an impression in sediment.

Front

What is a cast fossil?

Back

A fossil that forms when a mold is filled with minerals.

Front

What is a trace fossil?

Back

A fossil that provides evidence of the activity of an organism.