Two-Headed Porpoise Caught by Fishermen a Very Rare Find

Dutch fishermen found a dead two-headed porpoise in Holland's North Sea last month, but they threw it back into the ocean after recording a video, fearing that keeping the porpoise was against the law.

This two-headed marine mammal is one of only 10 documented findings of two-headed cetaceans (whale, dolphin, or porpoise), National Geographic reported. Conjoined wild mammals are much less common than conjoined humans, reptiles, and domestic animals.

According to The Telegraph, the two-headed porpoise died shortly after birth. The porpoise's tail, which these mammals use to swim when they're newborns, never stiffened.

"The anatomy of cetaceans is strikingly different from terrestrial mammals with adaptions for living in the sea as a mammal. Much is unknown," Erwin Kompanje wrote in a National History Museum Rotterdam study. "Adding any extra case to the known nine specimens brings more knowledge on this aspect."

Citing how rare it was for the group of fishermen to accidentally catch the two-headed creature, Kompanje said he wished they had held onto it.

"Normal twins are extremely rare in cetaceans," he added. "There is simply not enough room in the body of the female to give room to more than one fetus."

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