jun 13, 542000000 BC - Cambrian Period
Description:
In the early Cambrian, Earth was generally cold but was gradually warming as the glaciers of the late Proterozoic Eon receded. The middle of the Cambrian Period began with an extinction event. Many of the reef-building organisms died out, as well as the most primitive trilobites.
Added to timeline:
The History Of Earth
Date: