The name given by geologists for the period in Earth's history, and the strata of rocks laid down during the time, from about 541 to 485.4 million years ago (mya). Lasting 55.6 million years, its fossil deposits represent the earliest signs of animal life on Earth, and the numbers and diversity of the fossil forms has given it the name Cambrian Explosion. The name, given by the British geologist, Adam Sedgwick, derives from Cambria, the Roman name for Wales, where the rock strata was first explored.
The Cambrian is preceded by the Ediacaran Period (635-541 mys) and followed by the Ordovician (485.4-443.8 mya). The Cambrian is also the first of a larger era known as the Paleozoic Era (541-254.2 mya). In older literature, the Cambrian is known also as the Silurian.
©ALBERITH
281120lch