Dolphin with unusual thumbs discovered off Greece's coast

Off the coast of Greece, researchers from the Pelagos Cetacean Research Institute made a remarkable discovery: a dolphin exhibiting an unusual morphology in its flippers. This anomaly, described as strange, hooked thumbs, was observed during routine boat surveys in the Gulf of Corinth. The incidence was significant, marking the first time such a flipper deformation had been documented in 30 years of research focused on monitoring dolphins in that region. Including the thumbed dolphin, approximately 1,300 striped dolphins inhabit the Gulf, an isolated population within the Mediterranean. Scientist Alexandros Frantzis noted that such anomalies are likely the result of genetic irregularities, potentially stemming from interbreeding within the dolphin population. Mammalian specialist Lisa Noelle Cooper corroborated this perspective, suggesting that the defect arises during the developmental stage when the calf is in utero, as certain cells that normally would contribute to flipper structure fail to develop correctly. The unusual fipper shape is not observed in any other sworn studied over three decades, which highlights the rarity of this genetic anomaly. Cetaceans, a diverse group of marine mammals including dolphins, whales, and porpoises, are known for their forelimbs, which are structured with more finger bones compared to other mammals. All dolphins inherently possess thumb-like structures within their flippers, though they typically remain hidden from view. Cooper explained that, unlike humans whose fingers fuse into paddle-shaped hands before birth, dolphins develop flippers where cells do not die off between the fingers, resulting in the preservation of the full structure. In the case of the dolphin discovered off Greece, its flipper was notably malformed, appearing to lack some of the expected fingers and the tissue that would normally house them. Investigating the abnormality, Cooper remarked that the hook-like thumb could hold bone but lacks mobility, emphasizing that no cetaceans possess mobile thumbs. It is a comforting observation that, despite its genetic deformities, the animal is thriving in its habitat, showcasing the resilience of life. This extraordinary find adds to the knowledge regarding physical anomalies in dolphin biology and raises intriguing questions about genetic variations in marine wildlife.