In this paper, we present a detailed survey on the rodent fauna from the site of Barranco de los Conejos (Guadix-Baza Basin, southern Spain). Its rodent fauna is composed of three arvicolines (Orcemys giberti, Manchenomys oswaldoreigi, and Tibericola vandermeuleni) and two murids (Castillomys rivas and Apodemus atavus). The three arvicoline species present ever-growing molars. Orcemys giberti and Manchenomys oswaldoreigi can be considered as descendants of local Mimomys species (Mimomys medasensis and Mimomys tornensis, respectively), while Tibericola vandermeuleni is an eastern inmigrant. Loosening of roots in Orcemys giberti and Manchenomys oswaldoreigi is explained as an adaptation to a fossorial way of life, in relation to the Early Pleistocene glacial–interglacial dynamics, which led to cooler and drier conditions. This environmental change would also explain the dispersal of Tibericola from the eastern Mediterranean.

Key words: Mammalia, Rodentia, Muridae, Arvicolinae, Early Pleistocene, Guadix-Baza Basin, Spain.

Jordi Agustí [jordi.agusti@icrea.cat; ORCID: https://orcid.org/0000-0002-7240-1992], ICREA, Institució Catalana de Recerca i Estudis Avançats, Pg. Lluís Companys 23, 08010 Barcelona, Spain; IPHES-CERCA, Institut Català de Paleoecologia Humana i Evolució Social, Zona Educacional 4, Campus Sescelades URV (Edifici W3), 43007 Tarragona, Spain; Àrea de Prehistòria, Universitat Rovira i Virgili (URV), Avinguda de Catalunya 35, 43002 Tarragona, Spain. Pedro Piñero [ppinero@iphes.cat; ORCID: https://orcid.org/0000-0002-5626-2777], IPHES-CERCA, Institut Català de Paleoecologia Humana i Evolució Social, Zona Educacional 4, Campus Sescelades URV (Edifici W3), 43007 Tarragona, Spain; Àrea de Prehistòria, Universitat Rovira i Virgili (URV), Avinguda de Catalunya 35, 43002 Tarragona, Spain.