The micromammals association of the TD5- TD6 levels is exclusive from the karstic complex of Atapuerca (Burgos, Spain). This association is characterized by the presence of arvicolids : Terricola gregaloides, Terricola huescarensis, Terricola subterraneus, Microtus brecciensis, Arvicola chalirei, Mimorriys savini, Pliomys episcopalis, together two new rodent species: Terricola seseae nov. sp. and Microtus iignani nov. sp.. This fauna seems to correspond to the transit Lower Pleistocene - Middle Pleistocene, with more than 780.000 years ago, near of Matuyama/ Brunhes boundar
