Ancestral Instincts

Long ago,when Remnant was in its infancy,there were creatures that lived before humans were introduced. They,at the time,were called Fauna Sapiens,the ancestors of faunus and humans. They were almost completely animal,most were the size of humans except for the smaller animals such as mice.
They were about 4 feet when they stood on two legs,which the Fauna Sapiens could do. They could not speak the human language but they had brains similar to humans. They were both quadruped and bipedal.

There were two different lifestyles depending on which status you held in nature. Prey were nomadic people,never staying in one place and constantly on the move. Predators lived in a tribe-like society and would only travel to hunt prey. This continued for many ages,until Remnant spilt apart into the different continents.
The Fauna Sapiens located in Vale and Mistral were superb in technology and found no threats to their way of life and over time would evolve into humans.

On the other hand the Fennecs of Vacuo were excellent in technology as well but Vacuo's constant harsh temperatures made the Fauna Sapiens of Vacuo needs to keep their fauna traits and would evolve into the faunus. This was the same for Mantle as well as the snowy temperatures called for fauna traits,however much later when the humans arrived the still overwhelming faunus population would be reduced to slaves. While the humans would be in control of the technology.

The Fauna Sapiens had evolved into humans or faunus at this point.

For a time,everyone thought they were extinct...