Time span: 1 week. Full PDF can be found here: t.ly/bbowb
Artwork of my original species design, Cathedrals, on their home planet Chronanulus. Cathedrals are colossal exoskeletal herbivores. They are able to support their large size without an endoskeleton by making use of a porous, calcified outer layer, which supports them from the inside out like the flying buttress of a cathedral.
This porous layer originally began as a random mutation, and then proved to be adaptive in providing structural support. It hosts a myriad of floral, fungal, and faunal symbionts, both parasitic, mutualistic, and everything inbetween. It is like a massive, terrestrial coral reef.