Photo/IllutrationTwo dicynodont fossils found in Mine, Yamaguchi Prefecture (Akira Nemoto)

  • Photo/Illustraion

MINE, Yamaguchi Prefecture--Two fossil pieces found here were identified as the first indications that a distant ancestor of mammals roamed Japan when it was part of the Pangea supercontinent more than 200 million years ago.

The fossils were discovered in 2010 in stratum that dates back 230 million years in the Ominecho district of Mine, the city government said Feb. 13.

They were recognized as parts of the upper jawbone of a species in the dicynodont group of herbivores.

Dicynodont fossils have been excavated in many parts of the globe. Their widespread discoveries lend weight to the theory that today’s continents were once a single landmass known as Pangea during the Triassic Period.

According to Nao Kusuhashi, assistant professor of vertebrate paleontology at the Graduate School of Science and Engineering of Ehime University, the fossils found in Mine came from the latest period of the species’ existence.

“It is significant evidence that shows a dicynodont in its twilight once inhabited here,” said Kusuhashi, who examined the pieces.

One piece was about 12 centimeters long, while the other was about 7 cm long. The identification was made based on the formation of a fang and the surrounding bone.

Dicynodont species are characterized by two protruding fangs. Most of the animals are believed to have died out 210 million to 237 million years ago in the late Triassic Period of the Mesozoic Era.