Fossils found in 72-million-year-old sedimentary layers in Mukawa, a town in the northernmost prefecture of Hokkaido, have been confirmed as the largest complete dinosaur skeleton discovered in Japan, researchers have said.

The herbivorous dinosaur, a member of the Hadrosaurid family, is believed to have been 8 meters long and weighed 7 tons, Hokkaido University Museum Associate Prof. Yoshitsugu Kobayashi was quoted by Jiji Press as saying.

"Large dinosaur fossils tend to be exposed to wind and rain, which cause bones to deteriorate. Therefore it is rare for a complete skeleton to survive," said Kobayashi, who is studying the fossils together with the Hobetsu Museum.

"This is a historical discovery not only for dinosaur research but also for paleontology," he added.

Part of the skeleton was found in 2003 in layers of sediment that once lay on the seabed. At the time, the fossils were considered likely to be the remains of a marine reptile and were kept at the museum