Mineralized skeletons from Radiolaria and Diatoms reveal an iterative build-up of material along a cellular armature in response to an extreme shaping environment. Intense pressures from the ocean on all sides of the organism have evolved this semi-spherical shape with the emergent characteristics of internal struts and spikules for additional performance. Studied by the Biologist Ernst Haeckel in 1906 and by the engineer Frei Otto again in the 1960s, Radiolaria exemplify how geometry coupled with materiality can lead to exquisite elegance.