{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T09:06:52Z","timestamp":1789376812410,"version":"build-2803163510"},"reference-count":44,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,13]],"date-time":"2026-09-13T00:00:00Z","timestamp":1789257600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomolecules"],"abstract":"<jats:p>Molluscan shells combine mineralized layers with distinct microstructures that can influence crack propagation. Here, we provide a through-thickness, multiscale characterization of the all-aragonitic shell of the striped venus clam Chamelea gallina and relate its hierarchical textural organization to observed fracture-surface trajectories. Optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and spatially resolved Fourier-transform infrared spectroscopy and X-ray diffraction resolve an outer region comprising (i) convergent and divergent fibrous sublayers separated by a preferred fracture plane, (ii) a porous transition layer with inverse-tulip microstructures, and (iii) a structurally distinct homogeneous inner layer whose crossed-lamellar organization becomes visible after etching. The key advance is the resolution of this outer architecture from nanogranule alignment to curved fibrous layers and a porous transition region, together with the identification of recurring changes in fracture-surface direction at its interfaces. FTIR and XRD reveal through-thickness variations in vibrational-band ratios and crystallographic parameters. As the fracture analysis is based on post-fracture morphology, crack steering and damage localization are discussed as plausible structure-related mechanisms supported by the observed features. The architecture suggests transferable design principles, including graded orientation, interface-guided deflection, and localized porosity, for mechanically robust bioinspired composites and provides a structural framework for future studies of shell evolution and function.<\/jats:p>","DOI":"10.3390\/biom16091331","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T08:10:23Z","timestamp":1789373423000},"page":"1331","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Hierarchical Organization of the Layered Fibrous Shell of Chamelea gallina Guides Fracture Pathways"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1731-4578","authenticated-orcid":false,"given":"Devis","family":"Montroni","sequence":"first","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, University of Bologna, Via Piero Gobetti 85, 40129 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emilio","family":"Catelli","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, University of Bologna, Via Piero Gobetti 85, 40129 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Silvia","family":"Prati","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, University of Bologna, Via Piero Gobetti 85, 40129 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7797-5856","authenticated-orcid":false,"given":"Arianna","family":"Mancuso","sequence":"additional","affiliation":[{"name":"Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via Selmi 3, 40126 Bologna, Italy"},{"name":"Fano Marine Center, The Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, 61032 Fano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5022-9503","authenticated-orcid":false,"given":"Stefano","family":"Goffredo","sequence":"additional","affiliation":[{"name":"Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via Selmi 3, 40126 Bologna, Italy"},{"name":"Fano Marine Center, The Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, 61032 Fano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2367-3721","authenticated-orcid":false,"given":"Giuseppe","family":"Falini","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, University of Bologna, Via Piero Gobetti 85, 40129 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Lowenstam, H.A., and Weiner, S. 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