Named for Thalassa, the primordial Greek personification of the sea, the Thalassian Era is characterized by the dominance of marine life, with the oceans acting as the primary cradle for the complex, multi-layered ecosystems that would ultimately set the stage for life on land. 

During Earth’s Proterozoic Era, the earliest evidence of animals emerged, primarily in the form of soft-bodied organisms, including the Ediacaran biota, which were among the first multicellular life forms in Earth's oceans. Similarly, the early Thalassian Era saw a dramatic diversification of marine life and the emergence of Atmos's first large, multicellular organisms. 

Explore the Thalassian:

The Stromacene Epoch: 0-50 Million Years after the Protogenocian

The Tristagmacene Epoch: 50-150 Million Years after the Protogenocian

The Hyperpelagene Epoch: 150-200 Million Years after the Protogenocian

The Pelitolacene Epoch: 200-250 Million Years after the Protogenocian