When was the Cambrian period discovered?

The Cambrian period was first recognized in the early 19th century, with its name derived from the Latin term for Wales, "Cambria," where rocks from this period were first studied. The term was introduced by the geologist Adam Sedgwick in 1835, who used it to describe a sequence of rock layers containing ancient marine fossils. This period is significant for the "Cambrian Explosion," a rapid diversification of life forms that occurred approximately 541 million years ago.