This massive 'Blue Dragon' was likely an apex predator of ancient Japan's seawaters!

In the waters of Japan, a colossal creature as massive as the Great White Shark, once ruled as the ultimate predator. Resting in the sandstone of Wakayama Prefecture for 72 million years, this leviathan's remains surfaced in 2006, uncovering a forgotten era when immense sea creatures reigned supreme.

Paleontologist Akihiro Misaki stumbled upon the discovery while searching for ammonite fossils along the Aridagawa River. Instead, he unearthed a vertebra from a Mosasaur, an unseen species he termed the Wakayama Soryu or “Blue Dragon”. This creature was no ordinary Mosasaur, boasting four flippers — two front, two rear — alongside an exceptionally long tail, baffling scientists with its unique anatomy.

Takuya Konishi, a seasoned Mosasaur expert, found this specimen challenging conventional understanding. The creature's four flippers and whip-like tail contradicted known swimming styles of ancient marine creatures, posing a mystery about their functionality — whether for steering or propulsion.

Further revelations of a shark-like dorsal fin added to the enigma. Konishi theorised its role may have been in aiding swift turns while hunting. The front fins likely facilitated rapid manoeuvring, the rear aiding diving or surfacing, and the massive tail providing powerful acceleration.

Named Megapterygius wakayamaensi, paying homage to its region of discovery and its large flippers, this creature coexisted with the Tyrannosaurus rex in the Cretaceous period as the time’s apex predators. The Blue Dragon, a fossilized relic, offers a glimpse into a lost era, a testament to the wonders buried in the depths of time.

The detailed findings are available in the Journal of Systematic Palaeontology here.