Giglioli’s Whale is a supposed species of whale that was observed by Enrico Hillyer Giglioli. It’s known for having two dorsal fins as opposed to one or even none. The species, however, is not really recognized by the scientific community.
On the 4th of September, 1867 on a ship called the Magenta, Giglioli spotted whales that he could not identify. He observed for a quarter of an hour and wrote down very detailed observations. The whale looked similar to a rorqual whale, was 60 feet long with an elongated body, but the most notable feature was the two dorsal fins. No known whale has two dorsal fins as most have just one or even none. The next year there was another sighting of this kind of strange whale off the coast of Aberdeenshire in Scotland by Jacques Mairgret.
A possible explanation of this whale may be a genetic mutation. It is most likely just a species of rorqual that somehow ended up deformed or mutated by some means.