X-ray Study Reveals Narwhal Tusks Form 2 Opposing Spirals, Boosting Strength
Updated
Updated · Popular Science · Aug 18
X-ray Study Reveals Narwhal Tusks Form 2 Opposing Spirals, Boosting Strength
3 articles · Updated · Popular Science · Aug 18
Summary
Nature Communications published findings that narwhal tusks are built from two opposing helices—left-twisting outer cementum and right-twisting inner dentin—rather than a single spiral.
3D tensor tomography and other advanced X-ray methods mapped the tusk interior across atomic, nano and micro scales using synchrotron facilities in Sweden, Switzerland and France.
The opposing fibril patterns help explain how a tusk can stay straight while resisting bending and twisting better than a single spiral or straight rod.
Annual growth layers preserve the same twist pattern, suggesting a genetically fixed structure that could help researchers reconstruct narwhals' life histories and Arctic living conditions.