Assertion: tuatara's head | /r/CapableOf | play role
Facets:
value: in regulating circadian rhythms
type: OTHER
Source sentences:
text: The oddest feature of tuataras is their "third eye": a light-sensitive spot, located on the top of this reptile's head, which is thought to play a role in regulating circadian rhythms (that is, the tuatara's metabolic response to the day-night cycle).