Pterosaur fossil confirmed as nation’s largest by Professor Hirayama of the School of International Liberal Studies

A fossil (16.8cm long, 2.0cm wide) unearthed in the Amber Excavation Experience Site of the Kuji Amber Museum in Kuji City, Iwate Prefecture, and believed to be part of a pterosaur, has been identified to be an 85 million year old fossil from the Cretaceous Period by Professor Ren Hirayama, School of International Liberal Studies, Waseda University. This is the largest ever pterosaur fossil discovered in Japan and the first to be unearthed in the Tohoku region.

Pterosaurs were reptile-like creatures that were thought to have soared through the sky with enormous wings and are said to have become extinct at the end of the mid-Cretaceous Period about 65 million years ago.

According to Professor Hirayama the discovered fossil is 16.8cm long and the base of the fourth left finger (metacarpal bone: forms the back of the hand), corresponding to the middle of the wing. With a wingspan of three metres, equivalent to the size of a present-day albatross, it is relatively small for a pterosaur. Because the bones had a characteristic of being hollow inside, making the body light, it was understood to be a flying animal. Furthermore, because there was a large projection from the end of the bone, a feature unique to metacarpal bones of the pterosaur, it was clear that this fossil came from a pterosaur.

Because pterosaur bones are weak and brittle, fossil finds are extremely rare. There have been no more than six discoveries in Japan, and this discovery is the nation’s largest pterosaur.

Provided by Waseda University