01 / Designated fossil
A walrus-family fossil from the Tobetsu Riveris a specimen that fills a gap in evolution.
In 1977 a whale fossil was found in the Tobetsu River basin at Aoyama, and a walrus-family fossil is highly likely to be included in it. It was studied at the National Museum of Nature and Science. It dates to the late Miocene, about 9.5 to 10 million years ago. Its tusks are short, and it is thought to have eaten fish and squid.
- Designated a town cultural property on 16 Feb 2022
- Late Miocene, about 9.5 to 10 million years ago
- On deposit at the Hokkaido University Museum since 2015

