Castoroides Ohioensis (Giant Beaver) skull fragments

Help get Minnesota a State Fossil

Minnesotans, we need your help!

We asked what fossil form best represents our great state, and you overwhelmingly chose Castoroides ohioensis! Now, it’s time to let our voices be heard by the state legislature. Your help is integral in getting this fossil as an official state symbol.

Get involved!

Reach out to your legislators and let them know it’s long past time for Minnesota to join the ranks of states with an official state fossil, and share all you know about Castoroides ohioensis.

Castoroides ohioensis Fun Facts

This distant relative of the modern beaver was the size of a small bear.

Castoroides ohioensis is known as Ċapa in Dakota and Amik in Ojibwe.  

Nearly complete skeletons of this mammal have been found in each of the Twin Cities.

This large, beaver-like animal roamed the metro area and southern Minnesota during the last ice age.

This rodent of unusual size inhabited waterways and the developing glacial lakes as the ice receded across the state.

The last-known Castoroides ohioensis lived in North America about 10,150 years ago.

hand drawn image of Castoroides ohioensis (Giant Beaver)

Geologic age: About 1.9 million years to 10,150 years old, Pleistocene Epoch

Region in Minnesota: Twin Cities area and Freeborn County, Minnesota

EDUCATORS: Have a classroom full of fossil enthusiasts? Engage students in the legislative process as they meet the candidates and dig deeper into their campaigns.