precambrian
/priˈkæmbriən/
adjective
- Relating to the earliest geological time period, before the Cambrian period, covering most of Earth's history.
- Scientists study Precambrian fossils to understand early life forms.
- Precambrian rocks are some of the oldest on Earth.
- The Grand Canyon reveals layers of Precambrian rock at its bottom.
Synonyms
noun
- The Precambrian geological time period, spanning from Earth's formation about 4.6 billion years ago to around 541 million years ago.
- During the Precambrian, simple single-celled organisms appeared.
- The Precambrian covers about 90% of Earth's history.
- Geologists divide the Precambrian into several eons.