Photo/Illutration(The Asahi Shimbun)

  • Photo/Illustraion

KISARAZU, Chiba Prefecture--Researchers found part of the runner of a wooden sledge apparently used to construct a burial mound here 1,400 years ago.

It is only the second such discovery of "shura" and was unearthed during excavation work around the Matsumen kofun tumulus dating from the early seventh century.

V-shaped shura were used to haul heavy stones and other materials.

The artifact was discovered in 2014, but it was only recently that researchers were able to confirm its purpose.

The only other shura artifacts were excavated from the fifth-century Mitsuzuka kofun tumulus in Fujiidera, Osaka Prefecture.

The Kofun Period lasted from the late third to seventh centuries.

Calling the latest discovery important, the researchers said it sheds light on the spread of civil engineering in ancient times.

The fragment measuring about 140 centimeters was carved from Aphananthe aspera, commonly known as "muku" tree.

The Matsumen kofun tumulus, a rectangular tomb whose sides extend 45 meters, is part of the Hamanaga-Suga burial mound cluster. The artifact was discovered in a moat surrounding the site.

Because it was constantly exposed to water over the centuries, it did not rot, the researchers said.

Researchers assume that it took many people to haul a fully laden shura.

In 1978, two shura, a large one and a small one, were excavated from the Mitsuzuka kofun tumulus.

According to Kisarazu city’s board of education, the shura found here likely originally measured about 3.5 meters, a little larger than the smaller version discovered at the Mitsuzuka kofun tumulus.

Archaeologist Taichiro Shiraishi, who is honorary director of the Osaka Prefectural Chikatsu-Asuka Museum, said the shura was the right size for the construction work involved.

“It shows that shura were widely used on a daily basis across the Japanese archipelago in the Kofun Period,” he said.