How can one encapsulate a phenomenon in a name? Specifically, the way that some things in nature are simply not believed by the scientific or historical community and for centuries get written off as fantasy or delusion, but then eventually turn out to be real after all.
It is the exact opposite of a damp squib or pie in the sky, some belief or theory long espoused but which eventually turns out to be wrong.
The well-known Black Swan effect describes the discovery of something so seemingly bizarre, unknown and hitherto unsuspected that scientists at first refuse to believe the stories. But that is not quite what we want for something long reported but never accepted. The Coelacanth fish was believed to have been extinct for a hundred million years and when one was first identified in a fishing net the report was again disbelieved. Again, that is not it, for the phenomenon - the fish - was known to have once existed. Closer to what we want would be the elephant. Reported through travellers' tales and widely depicted in medieval times, it was thought to be a mythical beast for many centuries until eventually science had to admit its reality. But the "Elephant effect" risks confusion with the elephant in the room and suchlike metaphors. And anyway, Hannibal had known about elephants all right, back in the days of classical antiquity, they had just been forgotten. Aha! The giant squid fits the bill, throughout history known only through sailors' tales and the odd unconvincing decayed body part. Only in this new millennium were the Giant Squid Architeuthis and the even bigger Colossal Squid Mesonychoteuthis hamiltoni discovered by modern science. Here we go:
The Giant Squid effect describes any physical phenomenon long known through anecdotal accounts and dubious physical evidence, and therefore discredited by mainstream academia as fantasy, delusion, misinterpretation or outright fabrication, but which is eventually demonstrated to exist after all and at last comes to be recognised by the mainstream.
Here are some candidates on this blocki:
Updated 6 Sept 2019