Perspectives

Prehistoric Stone Tool Cut Out of Coral Reef and Taken Away in Kyushu island; Artifact was Believed to Have Been Dropped in Sea During Prehistoric Jomon Period

Courtesy of the Kikai municipal board of education, Kagoshima Prefecture
Left: The coral reef, seen in July 2019, when the tool was still integrated with it
Right: The coral reef, seen in August 2024, after the tool was cut out of it

By Ryuichi Sonoda / Yomiuri Shimbun Staff Writer

2:00 JST, December 27, 2024

KIKAI, Kagoshima — A stone tool, believed to be from Japan’s prehistoric Jomon period, which had become embedded in a coral reef on the seashore of Kikai Island, Kagoshima Prefecture, has been cut out of its place and is now missing, it has been learned.

The island’s municipal government is looking into preserving similar stone tools found at six other locations on the island.

According to the buried cultural properties center of the Kikai municipal board of education, the missing stone tool had been partially buried in a coral reef on the west coast of the island. It was reddish in color and about the size of an adult’s fist.

Nobuyuki Matsubara, chief researcher at the center, discovered at the site in March that a square portion of the coral reef, including the stone tool, had been scraped away.

This autumn, the town published a request for information in its public relations magazine, but the whereabouts of the stone tool and who took it remain unknown.

The island was formed about 100,000 years ago by rising coral reefs. The reefs continue to rise even now, at a rate of about 2 millimeters per year.

As the coral reefs near the seashore are more than 4,000 years old, the local government believes that the stone tools fell into the sea and became embedded in the surrounding corals over a long period of time before emerging above ground.

The site where the tool used to be is located on a shoreline with jagged rocks that offer poor footing. There is no signboard nearby to indicate the presence of the stone tool. Even on the island, only a few people knew its exact location.

Matsubara said: “It’s regrettable that the stone tool was lost. It’s a valuable artifact that provides clues to what people did during the Jomon period. We want to work hard to establish a system to protect other tools and raise public awareness.”