Scientists and culture experts in New Zealand have begun the first-ever dissection of a spade-toothed whale, the world's rarest whale species.

None has ever been seen alive at sea.

The list of what scientists don’t know about spade-toothed whales is longer than what they do know. They don’t know where in the ocean the whales live, why they’ve never been spotted in the wild, or what their brains look like. All beaked whales have different stomach systems and researchers don’t know how the spade-toothed kind processes its food. They don’t know how this one died.