Castoroides, also known as the Giant Beaver, existed during the Pleistocene in North America. They grew up to 8 feet tall and weighed between 130-220 pounds, making them the size of a black bear.
It’s unknown whether their feet were webbed and if they had a tail like the modern beaver since the soft tissue has decayed. The incisors of the Giant Beaver were 5.9 inches long. Their teeth structure was much different than the modern beaver, though. Modern day beavers have teeth that look like chisels that are good for gnawing on wood. Giant beaver teeth were bigger and broader.
The oldest fossils found are about 1.4 million years old, and scientists estimate that the beaver went extinct about 10,000 years ago, at the same time other large North American species like mastodons and mammoths also went extinct. Although it’s likely that humans had something to do with their extinction, there is no evidence of humans hunting giant beavers.