Aplodontia rufa, commonly known as the mountain beaver, is the world's most primitive rodent: elusive, destructive and often mean. But it just loves living in the damp Pacific Northwest.

The mountain beaver is neither a true beaver nor a confirmed mountain resident. Instead, the football-sized burrowing animal is, according to the Sequoia Park Zoo, one of the most primitive mammals… ...

Mountain beaver, which have no obvious tail, look somewhat like dark brown, footlong guinea pigs. They have tiny ears and eyes. Little is known of their biology except that they make burrows and ...

The mountain beaver (Aplodontia rufa) is a rodent that's adapted to burrowing, ... stumpy tails, and they don't chop down trees, build dams or live in lodges.

Study finds that the ancestor of the modern day mountain beaver had a larger relative brain size, offering a rare example of brain size decrease over time.