Proterozoic

The Proterozoic Eon spans an immense timeframe from 2.5 billion to 541 million years ago, marking the final chapter of the Precambrian. This eon witnessed some of the most critical environmental and biological transitions in Earth's history. Most notably, the proliferation of photosynthetic cyanobacteria triggered the Great Oxidation Event, flooding the atmosphere with oxygen and transforming global chemistry. This shift enabled the evolution of more complex, eukaryotic life-forms and, eventually, multicellular organisms. Geologically, the Proterozoic saw the stabilization of modern continental cratons and the formation of massive supercontinents like Rodinia. The climate experienced extreme fluctuations, including severe ice ages known as the "Snowball Earth" segments, where glaciers reached equatorial regions. The eon closed with the Ediacaran fauna, a unique group of soft-bodied multicellular creatures that paved the way for the later explosion of diverse skeletonized life.