Washington, Apr 29 (ANI): Researchers at Japan's Fukui Prefectural Dinosaur Museum have found an ancient rock containing a fossilized dinosaur skin.

The fossil is believed to contain traces of skin that fossilized before it fully decayed. Scientists say the unusual find is the first of its kind in Japan.

"It is extremely rare for skin to be preserved as fossil because, unlike bones, skin rots. Research on the fossil could help scientists restore dinosaurs in better detail," said Yoichi Azuma, assistant director of the museum.

Palaeontologists originally excavated the rock containing the fossil from a site called the Kitadani Quarry in Katsuyama. The layer was dated to the Early Cretaceous period, around 120 million years ago.

Within the rock, scientists noticed the skin traces and impression on a 9-inch-square, 2.7-inch-thick plate of fine-grained sandstone. The skin impression covers about 60 percent of the plate's surface and shows both polygonal and circular scales, each measuring a fraction of an inch.

Researchers believe the dinosaur that left its mark there probably collapsed and died on a wet surface. Sand covered the carcass before it fossilized.

Azuma said judging by the scale pattern and the shape of the imprint, it looked like the skin came from the leg of a plant-eating dinosaur, possibly a hadrosaur, an amphibious dinosaur with webbed feet and a duck-like bill.

"It could be from Fukisaurus, a 15.5-foot-long hadrosaur belonging to the subgroup iguanodontia. This subgroup includes some of the world's largest known veggie dinosaurs, some of which measured up to 50 feet long and weighed as much as eight tons. While not quite as hefty, the still-large Fukisaurus once roamed Japan. A full skeleton of this dinosaur was excavated near the location where the skin fossil was found," said Azuma.

"There is a possibility that clearer fossils of dinosaur skins will be found in the same area," he added.

Mark Goodwin, assistant director of the University of California Museum of Paleontology, said "the scale pattern might shed some light on what dinosaur it came from if comparisons could be made with dinosaur skeletons, such as hadrosaurs, from North America that have skin or skin impressions preserved over the bones".

"These are often referred to as 'mummified dinosaurs'," Discovery News quoted him as saying.

The dinosaur skin fossil will be on display at the Fukui Prefectural Dinosaur Museum in Katsuyama through May. (ANI)