Xióngxìng yījiǎojīng de cháng yá shíjìshàng shì yī kē tūchū de quǎnchǐ.
The long tusk of the male narwhal is actually a protruding canine tooth.
Tips
memory
Parse as 一 (one) + 角 (horn) + 鲸 (whale) — 'one-horned whale', a direct translation of the Latin genus name Monoceros ('single horn'). The 'horn' is actually a spiral left canine tooth that can grow nearly three meters.
culture
Medieval European traders sold narwhal tusks as genuine unicorn horns; the creatures have since been dubbed 'unicorns of the sea'. The Chinese name preserves the same 'single-horn' image.