# Research into narwhal tusk helical structure > Live situation record from CLSTR: https://clstr.news/situations/research-into-narwhal-tusk-helical-structure > Updated: 2026-08-22T07:53:36.000Z. Sources: 11. Developments: 2. An international research team has identified the biological mechanism responsible for the unique helical structure of the narwhal tusk. Using advanced 3D X-ray imaging and tensor tomography on specimens from Greenland, scientists discovered that the tusk is composed of two distinct layers of dental tissue that twist in opposite directions. The study, published in Nature Communications, explains that the outer layer of cementum forms a left-handed helix while the inner dentin forms a right-handed helix. This arrangement of mineralized collagen fibrils creates a biological counterbalance and internal tension, providing the tusk with the necessary hardness, strength, and flexibility to withstand hydrodynamic forces and Arctic conditions without breaking. While the structural engineering of the tusk is now clarified, the exact evolutionary purpose remains a subject of debate. Researchers suggest the tusk may serve functions ranging from sensory perception of salinity and temperature to social hierarchy and mate selection. ## Timeline ### 2026-08-22: Narwhal tusk structure explained by researchers Researchers have discovered that narwhal tusks grow straight due to two layers of dental tissue twisting in opposite spiral directions, providing strength and flexibility. 3 sources. https://clstr.news/cluster/narwhal-tusk-structure-explained-by-researchers ### 2026-08-18: Narwhal tusk helical structure decoded by international researchers Researchers have used 3D X-ray technology to reveal how the narwhal’s spiral tusk is formed by opposing microscopic helical structures that provide strength and flexibility. 8 sources. https://clstr.news/cluster/narwhal-tusk-structure-revealed-as-complex-biological-composite --- Cite as: Research into narwhal tusk helical structure. CLSTR, https://clstr.news/situations/research-into-narwhal-tusk-helical-structure