Man punches beaver in head. September 21, 2016. In this picture made available Thursday July 11, 2013, ... The beaver came out of the water, police said, and bit the man’s shoe.

No other studies have used stable isotopes to figure out the giant beaver’s diet. We studied fossil bones from giant beavers that lived in the Yukon and Ohio between 50,000 and 10,000 years ago.

And they were notably old, belonging to a giant beaver that lived and died in Minneapolis roughly 10,000 years ago. ... Turns out, Minnesota has a lot of state symbols.

In other words, as wetlands dried up, giant beavers ran out of food. They once ranged over much of North America but were extinct by about 10,000 years ago.