OSAKA — Researchers have recently discovered fragments of roof tiles within the grounds of Todaiji Temple in Nara that suggest the existence of another temple dating back to the early eighth century.

Shinji Yoshikawa, a historian at Kyoto University, and Tetsuo Hishida, a Kyoto Prefectural University archaeologist, said they discovered the tile fragments, about 100 pieces, by accident during a survey of the Todaiji grounds.

The fragments indicate the existence of a temple that could possibly be the forerunner of Todaiji, they said.

Known for its Great Buddha, Todaiji is believed to have been built in the 740s. The newly discovered tiles are older than that, the two said.

Yoshikawa said an electronic imaging sweep conducted in April on a 4,500-sq.-meter plot where the fragments were found detected what was believed to be the foundation of a large temple.

The tile fragments were found near the plot on a wooded slope on Mount Wakakusa, within the precincts of Todaiji.

Yoshikawa said it is likely the plot and the roof tiles are the remains of Konshuji Temple, believed to have been built in 728 and the main forerunner of Todaiji. The exact location of Konshuji has long been a mystery.

The roof tiles were mainly found on steep slopes on the southern and western sides of the plot. Most of the fragments bore a lotus-flower crest, which is also a feature of Kofukuji Temple near Todaiji. Kofukuji was established in 669 in Kyoto and was moved to Nara in 710.

Yoshikawa said the tiles were probably used to adorn a structure located on the mountain from 720 to 730.

Todaiji was built by Emperor Shomu, and its name first appeared in historical records in 747.

Konshuji, also built by Emperor Shomu on the death of his son, is believed to be one of several temples erected before Todaiji.

Yoshikawa said he believes a fire gutted Konshuji in 750 after it was struck by lightning.

Other experts expressed doubt about the Konshuji theory.

Shumpo Horiike, head of a research institute on the history of Todaiji, doubted the fragments indicate the remains of Konshuji, saying historical records of a memorial ceremony for Emperor Shomu’s son suggest the temple was not located on the mountain.

In 1998, Todaiji and Kofukuji were added to the U.N. Educational, Cultural and Scientific Organization’s World Heritage List.