Regolithic

The Regolithic Period is the most recent geologic period on the Rathnir-Eldham Geologic Time Scale, lasting from roughly 3.5 million years ago to the present day. It includes all of written history in the world, and witnessed the evolution of just about all of the world's sentient species (save for a few alien immigrants like the Raajjyn).

It is suspected that the same unknown forces that affected the world's magisphere to create the Great Climate De-Lateralization also guided evolution towards a humanoid body and intelligent mind at this time, as nearly every sapient species maintains a similar bipedal body form. Non-teleological evolution by natural selection, like what typically guides changes in organisms over time, cannot account for the extreme levels of convergence between the various peoples- humans, elves, animal-folk, etc.

The Regolithic Ice Ages began about 2 million years ago, cycling back and forth between periods of cold (glacial) and hot (interglacial). The most recent interglacial period began roughly 10,000 years ago, disrupting many early civilizations and separating Rathnir and Eldham, and many sub-regions of both, by vast expanses of water that were dry land during the glacial period. The end of the most recent ice age brought with it the extinction of a large number of megafauna like the Cavedigger Sloth and Giant Ocelot.