Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: 
For the first 4 billion years of Earth history there is only a little evidence of life. Organisms were tiny and soft and did not fossilize well. But scientists use a variety of ways to figure out what this early life was like. Note that the period from Earth's origin to the beginning of the Phanerozoic is called the Precambrian.


Question: What is the period from earth's origin to the beginning of the phanerozoic eon?
precambrian
Precambrian.