Creature Porn 04

Here's a concept all of you should be able to get mileage out of : The Keystone. It's that chunk at the center of a bridge that holds all the other chunks together. A "keystone" in a design could be anything, but once you've found it, all other decisions can arise from it. Experiment with the RELIEF of a keystone...its inner and outer qualities....the softness/hardness of its border. It CAN be flat, but it doesn't have to be!