The Fukui Prefectural Dinosaur Museum has announced the discovery of a fossilized bird that scientists believe dates back some 120 million years.
Museum officials said the fossil was found at the Kitadani formation of the Tetori group in Katsuyama, Fukui Prefecture, which is said to date back to the early Cretaceous Period some 120 million years ago. A complete fossil of a bird said to be from the early Cretaceous Period was previously found in China, but this is the first time for such a discovery to be made in Japan, and only the second time for a bird fossil to be found in Japan.
"This will prove valuable in learning about the evolution of birds and their geographical dispersion," said Yoichi Azuma, a special curator of the museum.
Museum officials said the fossil was found within a piece of rock measuring about 20 to 30 centimeters in length and width. Over 100 bones thought to be from the same specimen, including limbs, ribs and pelvic bones were preserved in a three-dimensional form. The fact that the upper forelimb bone was longer than the thigh bone led scientists to classify it as a bird. It was estimated that the bird measured about 60 centimeters in length and had a wingspan of about 1 meter.
Based on its skeletal form, the bird is thought to belong to the same group as the Sapeornis from the early Cretaceous period that was found in China's Liaoning province.
It is believed that primitive birds undergoing a process of evolution coexisted in the early Cretaceous period. A fossilized bird found in the Ishikawa Prefecture city of Hakusan that is believed to be about 130 million years old is held to be the oldest of its kind in Japan, but the latest fossil is said to be of a more primitive class.