Photo/IllutrationThe assembled skeleton replica of the Mukawa dinosaur in Mukawa, Hokkaido, Japan’s biggest-ever complete dinosaur fossil (Nobuhiro Shirai)

  • Photo/Illustraion
  • Photo/Illustraion

MUKAWA, Hokkaido--A dinosaur first found here in 2003, the largest-ever complete fossil unearthed in Japan, turns out to be a new species.

An international team comprising researchers from Hokkaido University and other institutes studying the approximately 8-meter-long "Mukawa" dinosaur skeleton, made the announcement on June 18.

"It's highly likely that the Mukawa dinosaur is a new type of dinosaur (under the Edmontosaurini tribe)," said team leader Yoshitsugu Kobayashi, a professor of stratigraphy and palaeontology at Hokkaido University Museum.

Kobayashi is expected to speak about the team's findings at a Palaeontological Society of Japan workshop to be held in Shizuoka from June 21.

The team arrived at the conclusion based on joint research conducted by Hobetsu Museum and other research institutes.

The Mukawa dinosaur has slight and thin forepaws, spurs turned sharply forward along its backbone and unique features on its cranial bones, according to the team's observations.

The unearthed creature is estimated to have been an adult at the age of 9 or older and weighed between 4 and 5.3 tons. The team also determined that the Cretaceous Period creature is part of the Edmontosaurini tribe under the Hadrosauridae family, according to a taxonomy analysis.

Segments of tail bones of the Mukawa dinosaur were discovered in 2003 from a geological layer dating to about 72 million years ago, in the late Cretaceous Period.

The rest of the bones were unearthed in 2017 followed by an unveiling of the creature's skeleton to the public.

With more than 80 percent of its bones having been discovered, the skeleton is said to be the largest complete fossil ever found in Japan.

The research team has submitted the compiled paper to a science journal for publication, and if the article is published, the dinosaur will officially be recognized as a new species.

Kobayashi told reporters at a news conference: "If it is recognized as a new species, it would be the eighth (new species found in Japan).

"The Mukawa dinosaur has many unique features not seen in other dinosaurs. We want to convey this to the world," he added.

A replica of the Mukawa dinosaur skeleton, as well as the real fossils, will be shown at the Dinosaur Expo 2019 event to be held from July 13 at the National Museum of Nature and Science in Tokyo’s Taito Ward. The museum and The Asahi Shimbun will be the primary organizers of the event.