The Cambrian Period was an evolutionary timeframe occurring about 541 million years ago, and lasting for about 55 million years. It was named for the Latin name for Wales (“Cambria”), which is where considerable fossil evidence was discovered.
The Cambrian Explosion was an event during that period. At that time, lifeforms began to rapidly diverge and evolve, leaving large amounts of fossil evidence.
The phrase “Cambrian explosion” is often used figuratively to refer to any time period where new forms of something rapidly begin to appear.
During the 1920s, there was “a Cambrian explosion of auto manufacturers”
Right now, in my hometown of Sioux Falls, there is a Cambrian explosion of car washes for some reason
Why I Looked It Up
I’ve heard the phrase several times over the years. I read about the literal form in a book about science history, and then heard the figurative form in some other context a few days later.