Mammalia - Rodentia - Cricetidae
Alternative combination: Mus pennsylvanicus
Synonym: Arvicola riparius Ord 1825
Belongs to Microtus according to C. J. Bell and G. S. Bever 2006
Sister taxa: Microtus agrestis, Microtus arvalis, Microtus australis, Microtus brecciensis, Microtus bucharicus, Microtus californicus, Microtus chrotorrhinus, Microtus drummondi, Microtus duodecimcostatus, Microtus epimticeps, Microtus guatemalensis, Microtus guentheri, Microtus guildayi, Microtus hibbardi, Microtus irene, Microtus kikuchii, Microtus leucurus, Microtus llanensis, Microtus longicaudus, Microtus mandarinus, Microtus meadensis, Microtus mexicanus, Microtus middendorffi, Microtus miurus, Microtus montanus, Microtus morlani, Microtus oaxacensis, Microtus ochrogaster, Microtus oeconomus, Microtus paroperarius, Microtus pinetorum, Microtus quasiater, Microtus richardsoni, Microtus rossiaemeridionalis, Microtus umbrosus, Microtus xanthognathus, Pitymys aratai, Pitymys cumberlandensis, Pitymys mcnowni, Pitymys nemoralis, Pitymys parvulus
Ecology: ground dwelling herbivore
Average measurements (in mm): m1 3.04 x 1.17, femur length 19.1, humerus length 14.6, radius length 16.8, scapula length 12.7, skull 26.5 x 14.8, tibia length 21.6, ulna length 14.9
Estimated body mass: 40.7 g based on femur length, humerus length, m1 length, tibia length, and ulna length