Hierarchical textures on aragonitic shells of the hyaline radial foraminifer Hoeglundina elegans

We studied the specific hierarchical architecture of aragonitic shells of a hyaline radial foraminifer, Hoeglundina elegans. The porous shells consist of an ∼50 nm thin top layer and columnar domains ∼1 μm wide and ∼5 μm long in which the c-axis is perpendicular to the surface. The domains are regarded as bundled pillars comprising iso-oriented nanograins ∼5 nm in diameter, and divided by lateral lines of nanoscale voids with an interval of ∼240–500 nm