![\"Margherita](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/Margherita_Bassi.png\")
<\/p>\nThe Arctic whales are the only known animals with straight tusks, and ones that consistently twist to the left. New research reveals that the inner layer twists to the right and that the opposing spirals provide strength and help the tusks grow straight<\/p>\n
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Margherita Bassi<\/a><\/p>\n | Daily Correspondent<\/p>\n August 20, 2026 11:11 a.m.<\/p>\n Narwhals live in the North Atlantic and Arctic Oceans. Narwhals are nicknamed the unicorns of the sea, and for good reason: The\u00a0Arctic whales<\/a>\u00a0sport a spectacular \u201chorn\u201d that can reach up to ten feet long. While they can\u2019t perform magic with this eye-catching feature\u2014technically a tooth\u2014researchers suspect the animals might wield their tusks to compete for mates, since mostly males have them, or use them as a sensory organ.<\/p>\n Their purpose is far from the only mystery, though. Narwhals are the only known creatures with a straight tusk, and one that visibly spirals to the left.<\/p>\n \u201cThe really special part is that these helices always have the same handedness\u2014similar to if all [people] only had left hands,\u201d Henrik Birkedal<\/a>, a chemist at\u00a0Aarhus University in Denmark, tells\u00a0Popular Science<\/a>\u2019s Laura Baisas. \u201cThis is, to the best of our knowledge, unique.\u201d<\/p>\n Now, in a study published August 18 in the journal\u00a0Nature Communications<\/a>, Birkedal and colleagues report that the elongated tooth actually contains two layers\u2014outer and inner\u2014that twist in opposite directions, making the tusk grow into a strong, straight structure.<\/p>\n Narwhal tusks visibly twist to the left.<\/p>\n Mads Peter Heide-J\u00f8rgensen<\/p>\n In the new work, the researchers examined several narwhal tusks, some of which were collected by Greenlandic Inuit subsistence hunters and others from the Greenland Institute of Natural Resources. A few got sliced up and examined under powerful microscopes and using intense X-rays. The team even put an entire narwhal skull, including the elongated tooth, in a C.T. scanner to create digital slices.<\/p>\n Analyses revealed that the tusk\u2019s building blocks\u2014firm but flexible threads of the protein collagen<\/a>\u2014had different arrangements. The one on the tooth\u2019s exterior, cementum, formed a left-handed helical layer. But the one on the interior, dentine, twisted into a right-handed helical shape.<\/p>\n These two \u201copposing spirals\u201d help the tusk grow straight, Birkedal tells\u00a0Scientific American<\/a>\u2019s Jackie Flynn Mogensen.<\/p>\n What\u2019s more, mechanical testing hinted that the different helices give the tusks strength, allowing them to withstand bending and twisting better than a single spiraled or nonspiraled rod. Overall, the work suggests that the intricate boundary between the cementum and dentine seems even more complex than researchers previously thought.<\/p>\n Fun fact: Narwhals might use their tusks to play<\/p>\n Aerial video footage included in a study published last year shows narwhals prodding and flipping a fish<\/a> in what looks like a play session.<\/p>\n![\"aerial](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/narwhal-group.jpeg\")
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\n Carsten Egevang<\/p>\n![\"closeup](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/narwhal-tusk.jpeg\")
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