Birds

Birds were creatures that existed in Rythulia during its early history. The are strongly implied to be extinct.

Rythulians were designed with birds in mind.

In the beta
Instead of Murals, players would have to find statues that resembled birds.

Speculation
The bird sound that gives the Chirp its name sounds the same as the one these birds made, suggesting that Wayfarers may be Rythulians that were given the power of the birds, or that Wayfarers and birds were even merged into the same creature.

It's possible that Ancient Rythulians revered birds, especially if the vision statues from the beta are any indication. If so, this would mean that the Wayfarers and their flight powers are especially important.