Photo/IllutrationA CT-based image of the fossilized bones of a lizard (Provided by the Mifune Dinosaur Museum)

  • Photo/Illustraion

MIFUNE, Kumamoto Prefecture—Fossilized bones unearthed in 2004 might be the first proof that a girdle-tailed lizard lived in Japan in the latter half of the Cretaceous Period (145 million years to 66 million years ago).

“There have been only a few reports even across the world about the discovery of fossils of land-based lizards dating from that epoch,” said Toshifumi Komatsu, an associate professor of geological paleontology at Kumamoto University.

“This is a globally precious find that could shed light on when and where girdle-tailed and similar lizards lived on Earth and why their numbers declined.”

Kenichi Chikushi, 36, had just graduated from Kumamoto University when he found the fossilized bones from a stratum in Mifune formed 90 million years ago.

When he entered the graduate school of the Open University of Japan in 2013, Chikushi resumed his study of the fossil.

CT scanning and other analysis of its internal structure showed a subcutaneous bone--a flat bone covering the body surface--inside the fossil.

The subcutaneous bone indicates the lizard was a type of girdle-tailed lizard or a related species that died out in the Cretaceous Period.

Girdle-tailed lizards appeared and declined during the Cretaceous Period. They are currently found in limited areas, such as Africa.

Fossils of a girdle-tailed lizard or the other species had never been found before in Japan.

The fossil also contains a rib and a vertebra, further indicating it is part of a lizard body. The creature is estimated to have been 30 centimeters long.

To determine whether the fossilized lizard is a new species, other parts of the creature must be found and more detailed surveys are required.

“I want to continue studying it in one way or another,” Chikushi said.

The fossilized bones are on display at the Mifune Dinosaur Museum.