In July 25, Hokkaido University began the Hadrosaurus family from the marine layer of the Upper Cretaceous Hakobuchi Formation (outer shelf deposits about 7 million years ago, within a water depth of about 7,200-80 m) distributed in Hobetsu, Mukawa-cho, Hokkaido. Skeletal fossils (200 caudal vertebrae) were found.Since then, the primary and secondary Hobetsu dinosaurs have been excavated.And this time, the cleaning of the fossils contained in many plaster jackets has been completed.When calculated by the number of bone parts, more than half of the bones were cleaned, and it was found that Mukawa Ryu is a whole-body skeleton.

　Dinosaur fossils have been found all over Japan, but whole-body skeletons are extremely rare.Since the Mukawa dragon this time is at least 8m long, it will be the largest whole-body skeletal dinosaur fossil in Japan.In addition, the whole body skeleton fossil is the first in Japan as a late Cretaceous dinosaur where dinosaurs prospered most.Furthermore, it is the first whole-body skeleton in Japan as a herbivorous dinosaur.While most of the dinosaur fossils found in Japan have been found in the terrestrial strata (layers deposited on land), Mukawa Ryu is the first whole-body skeleton fossil found in the sea strata.

　There are more than 50 species of Hadrosaurid dinosaurs, which can be broadly divided into two groups: Saurolophinae (or Hadrosauridae) and Lambeosaurinae.Although Kamuysaurus has both characteristics, current predictive analysis indicates that it is likely to belong to the Saurolophinae subfamily.However, the final conclusion requires further cleaning work and more detailed research.