Red Alert: Scientists Have Discovered a Dolphin With Thumbs

Here’s some news you probably didn’t expect to hear today: Scientists examining a unique society of mixed-species dolphins in Greece recently discovered a unique specimen… with thumbs. 

Dolphins are intelligent. But a major advantage we humans have, besides being able to walk on land, is our opposable thumbs. This particular dolphin’s thumbs are apparently not moveable (thankfully, for our species), and resemble a pair of bottle openers embedded in its flippers. 

The discovery was made by researchers from the Pelagos Cetacean Research Institute working in the Gulf of Corinth in Greece. The team shared their findings in a YouTube video uploaded in October. 

“The Gulf of Corinth is the only place in the world, where striped dolphins live in a semi-enclosed gulf, isolated from larger seas or oceans!” the researchers wrote in the video’s caption. “Together with common dolphins and Risso's dolphins, they form a permanent mixed-species dolphin society.” 

Among some other pretty notable observations, such as a common dolphin that adopted a “kidnapped” striped dolphin, the researchers wrote that they “recorded a unique striped dolphin with thumbs on both its pectoral [flippers].”

Needless to say, the discovery of a thumbed dolphin is spectacular. Live Science spoke to Alexandros Frantzis, president of the Pelagos Cetacean Research Institute, who told the outlet, “It was the very first time we saw this surprising flipper morphology in 30 years of surveys in the open sea and also in studies while monitoring all the stranded dolphins along the coasts of Greece for 30 years.”

So, what’s happening here? Have dolphins finally begun to evolve into a world-dominating species to rival homo sapiens? Live Science also spoke to Lisa Noelle Cooper, a professor who specializes in mammalian anatomy and neurobiology at Northeast Ohio Medical University, who said that it’s likely a genetic defect. Dolphins’ front limbs have a similar bone structure to our hands, the textbook example of the evolutionary concept of homologous structures, but instead cells form around them to form flippers.

"It looks to me like the cells that normally would have formed the equivalent of our index and middle fingers died off in a strange event when the flipper was forming while the calf was still in the womb," Cooper told the outlet.