Cambrian period
Life's explosive beginning
The Cambrian period is the earliest division of the Paleozoic era, spanning roughly 539 to 485 million years ago.
It marks the dramatic appearance of most major animal groups in the fossil record—the so-called Cambrian explosion.
Before this period, life was largely single-celled or soft-bodied; during it, creatures with hard shells and complex body plans proliferated in the oceans.
- OrdovicianPaleozoic geological period
- trilobiteExtinct segmented marine arthropod
- fossil recordRemains documenting prehistoric life
- Burgess ShaleCambrian lagerstätte in Canada
- geologic timeEarth's age measured epochally
Devonian · Silurian · Wales · stratigraphy · natural selection · fossils · early life · geochronology · stromatolites · tectonic plates · primordial · multicellular · sea · exoskeleton · explosion · ancient · extinction · evolution
- erasera, epoch, age, bronze age, period
- geologic timeeons, eon, epochs, era, epoch
- Paleozoic eraCarboniferous period, trilobites, brachiopods, Burgess Shale, ancient oceans
- paleosciencespaleontology, paleobiology, paleobotany, paleoclimatology, paleoecology
Cambrian periodAnthropocene
Proposed human-impact epoch
Precambrian · Cretaceous period · Jurassic period · modern era · mass extinction events