"Blue dragon" discovered that terrorized the Pacific seas 72 million years ago

Researchers have unearthed a new mosasaur in Japan, the “blue dragon,” that rivals the size of a great white shark, dating back 72 million years. This ancient marine predator, given the Japanese name Wakayama Soryu, offers new insights into the prehistoric seas of the Pacific.

Discovering the “blue dragon”

The Wakayama Soryu was found in the Wakayama Prefecture, along the Aridagawa River, by co-author Akihiro Misaki in 2006. It stands out for its exceptional size and unique physical features.

University of Cincinnati Associate Professor Takuya Konishi, a dedicated researcher of these ancient creatures, emphasizes the rarity of this find. “In this case, it was nearly the entire specimen, which was astounding,” Konishi remarks.

Unlike other mosasaurs, the Wakayama Soryu possessed extra-long rear flippers and a shark-like dorsal fin, features that likely enhanced its agility and speed in the water.

Konishi notes the surprising proportion of its anatomy. He said, “Its rear flippers are longer than its front ones. These enormous flippers are even longer than its crocodile-like head, which is unique among mosasaurs.”

The researchers have classified this specimen within the subfamily Mosasaurinae, giving it the scientific name Megapterygius wakayamaensis. This name, meaning “large winged,” aptly reflects the mosasaur’s significant flipper size.

Evolutionary insights of Wakayama Soryu

Konishi sheds light on the potential locomotive capabilities of the Wakayama Soryu. He surmises, “We lack any modern analog that has this kind of body morphology — from fish to penguins to sea turtles. None has four large flippers they use in conjunction with a tail fin.”

This unusual physical trait suggests a unique swimming technique, differing significantly from other known marine animals.

Mosasaurs, including the Wakayama Soryu, were apex predators in prehistoric oceans, existing from about 100 million to 66 million years ago. They lived alongside dinosaurs like the Tyrannosaurus rex but were wiped out by the same mass extinction event caused by an asteroid impact in the Gulf of Mexico.

“Blue dragon” cultural context

The naming of the mosasaur as “blue dragon” resonates deeply with Japanese folklore, where dragons are significant mythical creatures. “In China, dragons make thunder and live in the sky. They became aquatic in Japanese mythology,” explains Konishi, highlighting the cultural symbolism behind this naming.

The discovery of the Wakayama Soryu opens new avenues in understanding the diversity and evolution of mosasaurs. It challenges established notions of marine reptile locomotion and enriches our knowledge of the ancient oceans that once covered our planet.

As Konishi aptly puts it, “It opens a whole can of worms that challenges our understanding of how mosasaurs swim,” thus marking a significant milestone in paleontological research.

More about mosasaurs

As mentioned above, mosasaurs, the dominant marine predators of the late Cretaceous period, ruled the ancient seas with their formidable size and adaptability. These giant reptiles, often compared to modern-day whales and sharks in terms of their ecological role, represent a fascinating chapter in Earth’s prehistoric past.

Anatomy and evolution

Mosasaurs evolved from squamate reptiles, related to modern-day snakes and lizards. Their transition from land to sea marks a significant evolutionary journey. These creatures had elongated bodies, reaching lengths of up to 50 feet, with powerful tails for swimming. Their limbs transformed into flippers, enabling efficient movement in aquatic environments.

The skull of a mosasaur was robust, equipped with strong jaws and sharp, conical teeth, perfect for gripping and tearing flesh. Their dental structure varied across species, some adapted for crushing shells and others for slicing through softer prey.

Habitat and lifestyle

Mosasaurs inhabited a wide range of marine environments, from shallow coastal waters to the open ocean. Their fossils have been discovered globally, indicating their widespread presence during the Cretaceous period.

As apex predators, mosasaurs fed on a diverse diet including fish, mollusks, birds, and smaller marine reptiles. They were likely ambush predators, using their speed and agility to surprise prey.

Reproduction and behavior

Unlike many marine reptiles of their time, mosasaurs gave birth to live young. This adaptation allowed them to avoid the vulnerability of laying eggs on land and further solidified their dominance in the marine ecosystem.

While not much is known about their social behavior, some evidence suggests that mosasaurs might have exhibited schooling or pack-hunting behaviors, similar to some species of modern-day dolphins and sharks.

Extinction and legacy

Mosasaurs, along with many other species, fell victim to the mass extinction event at the end of the Cretaceous period, about 66 million years ago. This event, likely caused by a massive asteroid impact, led to significant changes in Earth’s climate and ecosystems, rendering these mighty creatures extinct.

Today, mosasaurs capture our imagination and contribute significantly to our understanding of prehistoric marine life. Their fossils provide valuable insights into the evolutionary history of reptiles and the dynamics of ancient marine ecosystems.

In summary, mosasaurs, the great marine lizards of the Cretaceous, represent an incredible chapter in the story of life on Earth. Their evolution, adaptation, and eventual extinction offer a compelling glimpse into the past, reminding us of the ever-changing nature of life on our planet.

The full study was published in the Journal of Systematic Palaeontology.

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