Assertion: narwhal's tusk | /r/HasProperty | single extremely long
Facets:
Source sentences:
text: Firstly, the most conspicuous characteristic of the male narwhal remains its single extremely long tusk.
text: The most conspicuous characteristic of male narwhals is their single extraordinarily long tusk, which is a tooth that projects from the left side of the upper jaw and forms a left-handed helix.