Viral 'Whale-Dolphin Hybrid' Spotted in Australia Is Impossible—Here Are Some Real Bizarre Ocean Matches

A dolphin jumps out of the surf at Snapper Rocks on the Gold Coast, Australia, February, 2015. Matt Roberts/Getty Images

A photo taken off the Gold Coast of Australia has people wondering if the picture could depict a dolphin, a shark, or a hybrid of the two. A shark-dolphin hybrid is impossible, but dolphins and their relatives have made some bizarre hybrids in the past.

Beachgoer Kellie Wilson posted the photo of the unidentified creature, asking readers what the animal could be. Some social media users were certain the animal in question was a dolphin and others saw a shark, briefly stirring a controversy reminiscent of "the dress." Some even suspected the animal was a hybrid of the two, according to The Daily Star.

The image shows a dark, long-bodied animal with fin arms, a finned tail, and a fin on its back. Is the animal a dolphin, a shark, or both?

It's definitely not both. Shark-dolphin hybrids are impossible. It's true that sharks and dolphins look similar in many ways, but that's because they are a product of convergent evolution, where two genetically distant animals who live similar lifestyles start to look and act in similar ways. But sharks are fish and dolphins are mammals. Their most recent common ancestor was an early jawed fish that lived around 290 million years ago. Dolphins are more closely related to deer than sharks.

A whale shark (L) and a bottlenose dolphin swim at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo, Japan. Different species of whales and dolphins have produced hybrid offspring. Yoshikazu Tsuno/AFP/Getty Images

But real life presents its own fascinating array of actual ocean hybrids. Dolphins are in the taxonomic order Artiodactyla, which includes all whales and hoofed animals with even numbers of toes. Cetaceans, or members of the whale family, including dolphins, have created hybrids both in captivity and in the wild before.

In March of 2016, researchers in British Columbia, Canada, published a study on cetacean hybrids in the journal Ecology and Evolution.

After reviewing the literature of documented hybrids in the whale family, they listed several surprising hybrids between entirely different animal genuses. The bottlenose dolphin, for instance, has mated with a variety of different species in captivity and in the wild, including with a Guiana dolphin, a Risso's dolphin, a short-finned pilot whale, and a false killer whale. In 2005, NBC reported that Sea Life Park in Hawaii was home to a "wholphin," a hybrid of an Atlantic bottlenose dolphin and a false killer whale. (False killer whales are technically a type of dolphin, and dolphins are technically whales.)

In the wild, a fin whale produced a hybrid offspring with a blue whale, a southern right whale dolphin mated with a dusky dolphin, and a narwhal mated with a beluga at least once, making a "narluga."

This skull comes from a “narluga,” or narwhal-beluga hybrid, captured in Greenland. It has a particularly large head and some erupted teeth—but unlike a beluga’s flat, peg-like teeth, they are shaped like tiny narwhal tusks. Picture and Caption via Mikkel H. Post, Natural History Museum of Denmark

The researchers concluded that whale and dolphin species that are more similar in physique, voice and behavior are more likely to hybridize. The scientists wrote that there is a need for more research into these hybrids to see how well they survive.

As for the animal in the photo? Sunshine Coast Daily reports that they contacted Sea World's resident marine expert Trevor Long for a verdict.

"I think it's definitely a dolphin," he told Sunshine Coast Daily. "It only looks like a flat tail because it's being distorted by the angle of the wave."