[Picture: Giant Beaver model at the Museum of Nature]
The Giant Beaver (Castoroides ohioensis) was a huge species of rodent, with a length up to 2.5 m (8.2 feet) and an estimated weight of 220 kg (485 lbs). It lived in North America during the Pleistocene epoch, and went extinct during the Würm glaciation, last Ice Age, 10,000 years ago.
The arrival of humans in the Americas is thought to be a factor in its extinction. It was one of the abundant Pleistocene megafauna - a wide variety of very large mammals that lived during the Pleistocene.