Just 37 million years after the Permo-Triassic mass extinction, the Triassic Period comes to an end with another mass extinction. It will require 100 million years for biodiversity levels to recover from the combination of these two neighboring devastations of life.
New species evolve. Diatoms with magnificent silica microshells appear and spread quickly throughout the seas. These micro mineral-magicians extract and cycle silica and other elements from the oceans.
Before these creatures evolved, the oceans were supersaturated with soluble silica. As each silica-forming group arose, silica concentrations decreased. Major accumulations of biogenic opal begin to cover the ocean floors of the world.