In July 25, 7 coccyx fossils were discovered in the marine layer of the Hakobuchi Formation of the Upper Cretaceous system distributed in Hobetsu, Mukawa-cho, Hokkaido.Subsequent excavations revealed that this dinosaur fossil was a whole-body skeleton, and became known as the "Mukawa Ryu."
Mukawa Ryu has about 6% of the bones (headbone, shoulder girdle, forelimbs, trunk vertebra, pelvic girdle, femur, caudal vertebra), and is the first large dinosaur in Japan to have such bones.And this time, a research group led by Professor Yoshitsugu Kobayashi of the Hokkaido University Museum conducted comparative research on bones, phylogenetic analysis, and histology of Mukawa dragon, and Mukawa dragon is a new genus and new species with unique characteristics. It was revealed that it is extremely likely that it is a dinosaur.
After finishing the cleaning work to remove the bone fossil from the rock, the work was done by joint research of Hokkaido University, Mukawa Town Hobetsu Museum, Okayama University of Science, American Perot Natural Science Museum, Tsukuba University, Mongolian Paleontological Geological Institute, and Tokyo University of Arts and Sciences. It was advanced.Mukawa dragons have many unique features not found in other dinosaurs, such as delicate and thin anterior legs and large forward tilts of protrusions (nerve spinous processes) that extend above the spine (torso vertebra). As a result of comparative studies, it is highly possible that it is a new relative dinosaur.Phylogenetic analysis revealed that Mukawa Ryu belongs to the Edmontosaurus (tribe) of the Hadrosauridae subfamily, and that it is closely related to Laiyangosaurus in China and Kerberosaurus in Russia.
Histological analysis of the inside of the hind legs (tibia) revealed that Kamuysaurus was an adult over 9 years old.From the thickness (peripheral length) of the humerus and femur, the weight was estimated to be 4 tons for bipedal walking and 5.3 tons for quadrupedal walking.
