Ri and Ilkai
Ri and Ilkai are the names given by tribes in Papua New Guinea to an elusive species of humanoid sea creature that is said to resemble mermaids. Although the existence of such a creature may be quite preposterous from an evolutionary viewpoint, the large number of reports coming from natives has proven very intriguing.
In 1983, two American scientists, zoologist Richard Greenwell and anthropologist Roy Wagner, set up an expedition into an area rich with Ilkai sightings, hoping to solve the mystery of the fabled sea people. The two men expected the creatures to be dugongs, seals or dolphins, mistaken for sea people by the locals. Nevertheless, after seeing the mysterious creatures terrorize small fish in a bay, Greenwell and Wagner drew the conclusion that Ilkai were indeed an unknown species, and that the natives knew very well the difference between them and other sea mammals. Unfortunately, the remoteness of the area and the lack of funding put an abrupt end to their expedition, and the sea people of Papua New Guinea remain a mystery to this day.