The numerous remains of beavers, mostly of Steneofiber eseri, from the lower Miocene site Ulm-Westtangente (MN 2a) are described. The metric and morphological variability of the population is depicted and compared with other beaver species as St. viciacensis from St. Gérand, St. eseri from Budenheim, Weisenau and Ulm, Trogontherium minutum rhenanum from Dorn-Dürkheim, St. depereti and Palaeomys. These comparisons allow to conclude on the evolution of the European beavers during the Miocene.