Scientists in Japan have made a remarkable discovery, unearthing the near-complete remains of a colossal sea creature that dominated the ancient Pacific Ocean. This incredible find has been named the “blue dragon” due to its unique characteristics, setting it apart from any other aquatic animal, past or present.
The exceptional fossils, estimated to be around 72 million years old, were found along the Aridagawa River in Wakayama Prefecture on Honshu Island. They belong to a previously undiscovered species of mosasaur, a group of air-breathing aquatic reptiles that were apex predators during the Cretaceous period (145 million to 66 million years ago). This discovery is considered the most complete set of mosasaur fossils ever found in Japan and the northwest Pacific.
In a recent study published in the Journal of Systematic Palaeontology, researchers introduced the new species as Megapterygius wakayamaensis. The name “Megapterygius” translates to “large-winged,” referencing its unusually large rear flippers, and “wakayamaensis” honors the prefecture where it was discovered. To add a touch of mythology, the researchers affectionately nicknamed the creature the “Wakayama Soryu,” with “soryu” meaning a blue-colored aquatic dragon in Japanese folklore.
Mosasaurs typically share a similar body plan, with minimal variation among species. However, Megapterygius wakayamaensis stands out as an outlier, surprising scientists with its unique features.
The creature had a dolphin-like torso, four paddle-like flippers, an alligator-shaped snout, and a long tail—typical features of mosasaurs. What makes it extraordinary is the presence of a dorsal fin, similar to those found in sharks or dolphins, a feature not observed in other mosasaur species.
The most puzzling aspect for researchers was the size of the creature’s rear flippers, which were unexpectedly longer than the front flippers. This characteristic is extremely rare among all living and extinct aquatic species, challenging our understanding of aquatic anatomy.
Unlike most swimming animals, which have larger flippers at the front for efficient steering, Megapterygius wakayamaensis had an unconventional body structure. The researchers speculate that instead of using the longer rear flippers for steering, the creature angled them upward or downward, possibly for quick dives or ascents through the water column. The dorsal fin might have assisted in turning, compensating for the extra drag caused by the extended rear flippers.
