Analysis by an X-ray fluorescence analyzer shows how mercury is dispersed on the wall at Kitora Tomb to depict the head of the snake. Experts believe it depicts the snake's long red tongue. According to a study done by the Agency for Cultural Affairs, richly colored murals at Kitora Tomb in Asuka, Nara Prefecture have been confirmed to include the Chinese zodiac animals of the dragon, the snake and the monkey.
The findings were reported at a study conducted by the Agency for Cultural Affairs about the tomb in Tokyo on March 23.
Ryusuke Masuki, an associate professor of history of Buddhist paintings at the graduate school of the University of Tokyo, said he was surprised at how well preserved the paintings are.
The Kitora Tomb is an ancient tumulus believed to have been made between the late seventh century and the early eighth century.
The tomb is designated as a special historic site by the government.
The murals at the Kitora Tomb have been designated as a national treasure.
The paintings of the 12 Chinese zodiac animals depict the creatures with animal heads and human bodies.
Experts believe three animals were painted on the east, west, south and north walls of the tomb.
Some of the walls are covered in mud, so the animals can't be seen easily.
Experts had confirmed six of the 12 animals paintings at Kitora Tomb until the latest finding.
The six animals included the tiger and the horse.
In February, a research team from the study meeting analyzed portions of the Kitora Tomb's walls where they assumed the three animals - the dragon, the snake and the monkey - using an X-ray fluorescence analyzer.
They assumed that the three animals were painted on the east, south and west walls.
The research team looked at how elements in the pigment were dispersed on the walls.
As a result of the presence of mercury and copper on the wall, the team determined how to tell the three creatures they had animal heads and human bodies.
The team could clearly recognize the clothes the snake is wearing in the painting, as well as the shapes of its head and tongue.
The use of mercury suggests that painters used red pigments, while the use of copper hints suggests they used blue and green pigments, according to the team.
Masuki believes that the painting of the snake on the wall depicts its long red tongue.
Similar pictures of the 12 Chinese zodiac animals are included in collections of Buddhist images from the Heian period 794 -- 1185, he said. The finding further clarifies the historical importance of the Kitora Tomb murals.