The mountain type of this, seen here, is the most primitive living rodent
Most people don't know mountain beavers exist and some still 
continue to ... they are only occasionally seen wandering around on the ground 
or climbing in trees... [DOC] [TLE] Rodents - Mount Rainier National Park (U.S. National Park Service) [PAR] Rodents, in terms of numbers, are the most successful group of mammals in the 
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