The Wakayama Soryu, a newly described mosasaur known as the “blue dragon,” possessed a shark-like dorsal fin.
Researchers have detailed a mosasaur from Japan, comparable in size to a great white shark, that dominated the Pacific waters 72 million years ago.
The extended length of its rear flippers likely enhanced propulsion, working in tandem with its elongated finned tail. Unlike other mosasaurs or large extinct marine reptiles, this
“In China, dragons make thunder and live in the sky. They became aquatic in Japanese mythology,” he said.
Unique Features and Classification Challenges
The specimen was discovered along the Aridagawa River in Wakayama by co-author Akihiro Misaki in 2006. The specimen is the most complete skeleton of a mosasaur ever found in Japan or the northwestern Pacific, Konishi said.
“In this case, it was nearly the entire specimen, which was astounding,” Konishi said.
He has dedicated his career to studying these ancient marine reptiles. But the Japanese specimen has unique features that defies simple classification, 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.
“I thought I knew them quite well by now,” Konishi said. “Immediately it was something I had never seen before.”
Apex Predators of the Prehistoric Oceans
Mosasaurs were apex predators in prehistoric oceans from about 100 million years ago to 66 million years ago. They were contemporaries of Tyrannosaurus rex and other late DOI: 10.1080/14772019.2023.2277921
The study was funded by NSERC.