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The oldest record ofCricetodon(Cricetidae, Rodentia, Mammalia) from the Aragonian type area (Calatayud-Daroca Basin, Zaragoza, Spain) is described. The remains from Las Umbrías (LUM) and Las Planas (LP) sections are attributed toCricetodon soriae, described in the locality Somosaguas N (SOMN) from the Madrid Basin (biozone E, MN5). The studied material (including 52 jugal teeth) belongs to eight localities spanning a time interval from 14.06 to 13.80 Ma, covering the entire biozone E. A morphometric analysis of the Calatayud-Daroca material provides the most specific and detailed descriptions ofC. soriaeuntil now. New complete descriptions of the type material from SOMN and an emended diagnosis ofC. soriaeare presented. Comparisons with all the species ofCricetodondescribed to date have been made. Differences betweenCricetodon aureusandCricetodon meiniare discussed; the results yielded by the study of more than 100 upper third molars from Vieux-Collonges make it possible, for the first time, to distinguish between those ofC. aureusandC. meini, and to compare them both withC. soriae. The presence of common characteristics indicates a closer relationship ofC. soriaewith the species ofCricetodonfrom Asia Minor than with the first representatives ofCricetodonin central and eastern Europe. The distribution ofC. soriaein the Iberian Peninsula is coincident with the global cooling event and the increasing in aridity in southwestern Europe, and the faunal dispersion event calledConohyus/Pliopitechusthat took place during the local biozone E. [ABSTRACT FROM PUBLISHER]

A new species of Gliridae (Rodentia, Mammalia), Microdyromys remmerti, sp. nov., from the Aragonian type area in the Calatayud-Montalban basin (Miocene, Spain) is described. This species is characterized by combining a relatively large size and a moderately complicated to very complicated and irregular dental morphology. It has a wide and continuous range of morphological variation with intermediate forms filling all the range. In the studied localities, M. remmerti, sp. nov., displays a general increase in the complexity of the dental pattern through time, showing a unique pattern of addition of extra ridges in the lower molars. Comparisons with morphologically similar species are discussed; a taxonomical and nomenclatorial issue regarding two named species of the genus is clarified. The combination of the morphometrical features that characterize M. remmerti, sp. nov., have never been found in any other glirid material outside the Calatayud-Montalban basin, thus reinforcing the idea of the endemic character of the Gliridae faunas from the Iberian Miocene. Microdyromys koenigswaldi is proposed as most probable ancestor of M. remmerti, sp. nov. The divergent evolution of the latter species is discussed in its paleoecological context. The functional consequences of this morphological divergence could be related also with the opening of new ecological niches during the middle Aragonian (Middle Miocene). [ABSTRACT FROM AUTHOR]