Rarest moth?

Titanomis sisyrota is probably the rarest moth in New Zealand.

Titanomis is quite big, with a wingspan of 55-63 mm.
Only 10 have ever been found, and none since 1959, when 1 was caught at floodlights on the Waipapa Dam.
Some other moths are known from fewer specimens, but most of these are very small, and easily overlooked.
So unusual is Titanomis that experts don't even know which group of moths it belongs to!