- A dolphin who appears to have thumbs was spotted in waters off mainland Greece.
- Researchers photographed the dolphin, whose flippers are deformed, to look like a hand with a thumb.
- The dolphin is living well with what researchers believe to be a genetic defect.
Who doesn't love to watch a pod of dolphins swimming and playing in their natural habitat? Researchers with the Pelagos Cetacean Research Institute noted a strange-looking dolphin in July 2023, who appeared to have thumbs.
Let's dive into how rare it is to see a dolphin with thumbs, how it might have happened, and whether this dolphin faces any particular challenges with this oddly-shaped flipper.
A dolphin with thumbs was observed in the Greek Gulf of Corinth.
In the Gulf of Corinth off the coast of Greece, scientists came across a striped dolphin sporting a strange sight: thumbs where they would normally have just two flippers. According to Live Science, the discovery was made by researchers from the Pelagos Cetacean Research Institute. Experts say that the strange condition for this dolphin is most likely due to a genetic defect.
Alexandros Frantzis, president and scientific coordinator of the institute, took photos of the rare dolphin. He said, per Live Science, that the dolphin's strange appearance could be "the expression of some rare and 'irregular' genes" as a consequence of interbreeding.
As the New York Post reported, associate professor of mammalian anatomy at the Northeast Ohio Medical University, Lisa Noelle Cooper, also said the dolphin's thumbs were likely due to changes in the genes. She also noted that these thumbs don't serve a purpose the way humans' thumbs do; in other words, they're not opposable.
Do dolphins have thumbs?
In a way, yes, dolphins do have thumbs, but they are typically hidden by the mammals' flippers, doctoral student Bruna Farina explained to Live Science. Dolphins are a member of the cetacean marine mammal group (porpoises and whales are also a part of this) and they have a larger number of phalanges than other mammals, which are covered by flippers.
According to the Dolphin Research Center, the pectoral fins of dolphins are skeletally very much like the human hand. In fact, dolphins have a "complete hand structure, including five phalanges, or finger bones." They even have a radius, ulna, and humerus. Given this information, it's not all that surprising that a dolphin has thumbs; they're just not normally visible due to their being surrounded by flippers.
Cooper said that this particular dolphin was likely born without all of their fingers or the covering for them, so instead what researchers see on the dolphin is only the "thumb" and what might be considered the ring finger, per the New York Post.
According to UNILAD, Frantzis commented on the rarity of this dolphin: “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.”
NDTV reported on the dolphin with thumbs as well, noting that the mammal was seen "swimming, leaping, bow-riding, playing" and did not appear to be hampered at all.