Complete dinosaur skeleton discovered in Japan
The bones of the dinosaur Mukawaryu which have been cleaned so far, that likely represent more than half of the bones the dinosaur had. Hobetsu Musem/The Hokkaido University Museum

Researchers have unearthed the complete skeleton of an herbivorous, duck-billed dinosaur (Hadrosauridae) in Japan. The fossil measuresat 8 metres long, which according to researchers, makes it the largest ever dinosaur skeleton found in Japan.

The dinosaur fossil was found in the Hobetsu district of Mukawa Town that lies in the northern island of Hokkaido, and the marine deposits from which the skeleton was excavated date back to 72 million years.

Although the exact species of the dinosaur currently remains unknown, scientists have nicknamed the dinosaur "Mukawaryu" (Mukawa dragon).

The reason for the mystery surrounding the dinosaur's exact specimen type stems from the fact that there are over 50 kinds of hadrosaurid dinosaurs, which are classified into two groups – uncrested (Hadrosaurinae) and crested (Lambeosaurinae).

"Although Mukawaryu has some characteristics of both groups, our preliminary analysis indicated it might belong to the Hadrosaurinae. Further cleaning of the fossils and detailed research should make it clearer which group the Mukawaryu skeleton belongs to," lead researcher Dr. Yoshitsugu Kobayashi said in a statement.

The fossil was first discovered in 2013, when paleontologists from Hokkaido University and Hobetsu Museum in Mukawa began the excavation process. The discovery marks the third such find in the world – of a complete skeleton of an undescribed specimen to have been unearthed from a marine stratum.

"We first discovered a part of the fossilized Mukawaryu skeleton in 2013, and after a series of excavations, we believe we have cleaned more than half of the bones the dinosaur had, making it clear that it is a complete skeleton," Kobayashi said.