Fig. 2: Convergent designs of struts.
Main needs and sustained forces driving the evolution of the strut design strategy. Key extinct and extant examples of this convergent design: sea urchin skeletons feature a highly complex trabecular architecture, which offers a combination of lightness and mechanical robustness through variations in density, topology, and composition50; diatom thecae exhibit a unique hierarchical geometric porosity that provides multifunctional properties, such as lightness, mechanical strength, optical performance, and filtration capability139; Glyptodon body armor is composed of ossicles with a sandwich structure, which delivers impact absorption, space for vascular systems, and thermal insulation139.
