cambrian
/ˈkæmbriən/
adjective
- Relating to the earliest period of the Paleozoic era, from about 541 to 485 million years ago, when many major groups of animals first appeared in the fossil record.
- Scientists study Cambrian rock layers to understand early animal evolution.
- The Cambrian period saw a rapid diversification of life known as the Cambrian explosion.
- Fossils from the Cambrian era are found in rocks all over the world.
noun
- The Cambrian period or the system of rocks deposited during that time.
- The Cambrian is famous for the sudden appearance of complex life forms.
- Geologists divide the Cambrian into three series: Lower, Middle, and Upper.
- Many trilobite fossils date back to the Cambrian.