Assertion: narwhal's tusk | /r/HasProperty | incisor
Facets:
Source sentences:
text: The tusk is actually an incisor that grows through the upper lip of the male Narwhal but is it used for piercing the arctic ice or
text: The most conspicuous characteristic of the male narwhal is its single 2–3 meter (7–10 ft) long tusk, an incisor tooth that projects from the left side of the upper jaw and forms a left-handed helix.