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[EN] One of the most important contributions of Nieves López Martínez in Palaeobiogeography is the study of the ‘centre of origin of species’ concept and the proposal of the ‘Asymmetric Time Model’ as an alternative to the ‘Symmetric Time Model’, a key concept in dispersalist Historical Biogeography. As a consequence of these ideas, she discussed the methodology to establish biostratigraphic scales, pointing out that the higher number of ‘First Appearance Datum’ (FADs) over that of ‘Last Appearance Datum’ (LADs) in the fossil record supports the Asymmetrical Time Model. In this study we analyse the middle Miocene micromammal appearance and extinction events (FADs and LADs) based on well-calibrated local biostratigraphic scales from different European basins, in order to determine which of the proposed biogeographical models better fits the Miocene European micromammal record. [ES] Entre las aportaciones de Nieves López Martínez a la Paleobiogeografía, se puede destacar el estudio del concepto de ‘centro de origen de un taxón’ y la propuesta del ‘Modelo Temporal Asimétrico’ como alternativa al ‘Modelo Temporal Simétrico’, concepto básico de la Biogeografía Histórica dispersalista. A partir de estas ideas analizó la metodología de construcción de las escalas bioestratigráfi cas, señalando que el mayor número de eventos de primera aparición (FAD) en el registro fósil frente a los de última aparición (LAD) confirmaría el Modelo Temporal Asimétrico. En este trabajo se analizan los eventos de aparición y extinción (FADs y LADs) reconocidos en escalas bioestratigráficas locales bien calibradas de diferentes cuencas europeas, con el fin de comprobar cuál de los modelos biogeográficos se ajusta mejor al registro europeo de micromamíferos miocenos., This work is a contribution to the Spanish MICINN/MINECO projects CGL2008-04200/BTE, CGL2011-28877, and the Universidad Complutense de Madrid Research Group UCM-910607 “Evolution of Cenozoic Mammals and Continental Palaeoenvironments”. IG-P is supported by a JAE-Doc contract (CSIC program “Junta para la Ampliación de Estudios”, co-funded by the European Social Fund) and by the Spanish MICINN/MINECO project CGL2010-21672. PL-G acknowledges a UCM Predoctoral contract and a “Martin Fellowship” grant at the NBC (The Netherlands). VHB and AO are supported by FPI and FPU predoctoral contracts (MICINN/MINECO), respectively

Corral de Lobato, a karstic site in the area of Molina de Aragón has been studied in a preliminary way. Even though there are not many Neogene karstic sites in the Iberian Chain, they occur in four clusters, with ages ranging from latest middle Miocene (MN7/8) to early Pleistocene (MN17). Correlations between these clusters and the reference stratigraphical units of the Tagus Basin, as well as with local and global events, are proposed. These karstic sites provide a complementary source of fossil vertebrate remains to that of the stratified sites formed lowland. The Heritage significance of such sites arises from the enhanced preservation of rare taxa or associations, and the operation of biotic concentrative processes., This work received financial support from the research projects CGL2015–68333-P (MINECO/FEDER, UE), Research Group BSCH-UCM 910607 and Consolidated Research Group EO5 (Aragón Government).

The works carried out in the Madrid area during the last fifteen years have yielded almost twenty new localities including small-mammals. A taxonomical description of the rodent fauna of the new sites and a revision of those previously published has enabled us to present an updated biostratigraphy and biochronology for the middle and upper Aragonian of the Madrid Basin. Seven local biozones are recognised: Db, Dc, Dd, E, F, G1 and G2. The rodent assemblage of biozone Db is here described for the first time in Madrid. The new finds have also filled poorly-known parts of biozones Dc, Dd, E and F, making now the rodent assemblages of biozones Dc and E from Madrid one of the most complete and best-represented records. Considering the faunal variability in biozone G1 in the Madrid Basin, we propose a new definition for it. The comparison of the rodent assemblages between the Madrid and Calatayud-Montalbán basins points out that both share several similarities in their taxonomical distributions, although with less diverse faunas in Madrid. A relative impoverishment in taxa of complicated dental pattern in Madrid could be interpreted as due to differences in the local environment with Calatayud., This work was supported by the Spanish MICINN [Ministerio de Ciencia e Innovación] projects [CGL-2008-04200/BTE], [CGL2011-28877]; VH-B was supported by a FPI pre-doctoral contract.

Remarkable palaeoclimatic global changes have been recorded worldwide during the middle Miocene. The Miocene Climatic Optimum (~ 16.3 to ~ 15 Ma), one of the warmest phases since the Eocene, was followed by the stepwise cooling trend of the Middle Miocene Climate Transition (~ 15 to ~ 13.7 Ma). The entry into an Earth “Ice-house” climate state took place at the end of the latter (~ 13.76 Ma) marked by one of the major cooling steps in middle Miocene climate recorded at a global scale (Mi3b event). The Madrid Basin, which is part of one of the main Cenozoic basins of the Iberian Peninsula, contains a well-represented small-mammal record from the lower middle Miocene to the upper middle Miocene (middle and upper Aragonian, ~ 15.9 to 12.8 Ma), being an appropriate region to check how these climatic phases influenced the distribution of the mammalian faunas on the center of the Iberian Peninsula. Values of species richness, equitability and heterogeneity of rodents have been calculated for 25 localities of the Madrid Basin and compared to detailed climate isotope records from the marine realm (ODP Site 1146 from the South China Sea and the Mediterranean record of the Ras Il Pellegrin section on the Maltese Islands) and with palaeoprecipitation curves for southwest Europe (Calatayud-Montalbán Basin). The results show that the rodent community during the middle and upper Aragonian in the Madrid Basin was subject to the changing climate conditions imposed in the course of the middle Miocene. The palaeoecological curves witness periods of disturbance of the community during changing climate conditions (marked by important drops in equitability and, in some cases, gradual decreases in heterogeneity and species richness), followed by periods showing a recovery of the community and adaptation to the new climate circumstances (represented by more evenly distributed and diverse assemblages). The effects of the Miocene Climate Optimum and of three Mi-events (Mi2b, Mi3a and Mi3b) have been related to changes in the small-mammal community. Between ~ 15.8 and 15.3 Ma, the likely extreme environment (high temperature and low precipitation) of part of the Miocene Climate Optimum may have imposed severe constraints on the fauna, resulting in a community with low values of equitability, heterogeneity and a decreasing number of species. The transition of the Miocene Climate Optimum to the Middle Miocene Climate Transition, reflected by the Mi2b event, has also procured a destabilization of the rodent assemblages, as an important drop in equitability is recorded between ~ 15 and 14.6 Ma. In this interval, the drop in temperature and increase in rainfall derived from the Middle Miocene Climate Transition promote the southwards migration of northern invaders, leading to an increase in species richness in the Madrid Basin. Starting around 14.4 Ma, the onset of a progressive drop in the rodent equitability and heterogeneity, which also coincides with a major stratigraphic discordance in the basin, is related to the first cooling step of the Middle Miocene Climate Transition (Mi3a event). Finally, the major cooling step in middle Miocene climate recorded at a global scale (Mi3b event) is poorly reflected in the palaeoecological curves. However, the taxonomical study of the rodent faunas of that interval (biozone E) has shown turnover rates and morphometric changes that indicate that this period represents one of the most variable in assemblage composition within the Aragonian. Although the Mi3b event has been correlated for a long time to the substitution of the early-middle Aragonian fauna by a late Aragonian community (E–F boundary), the study of the rodent assemblages of the Madrid Basin may point out that small changes in the small-mammal community started before (within biozone E)., This work was supported by the Spanish MICINN projects CGL-2008-04200/BTE and CGL2011-28877.

[EN] We present an updated taxonomy and faunal distribution of the micromammal fossil record from the Aragonian and Lower Vallesian of the Calatayud-Montalbán Basin. The analysed record includes the orders Rodentia, Eulipotyphla, and Lagomorpha. The pattern of species turnover shows seven major faunal events, which are correlated with major climate changes based on marine stable oxygen and carbon isotope records. Episodes δ18O Mi-2 and Mi-3 are significantly correlated with major micromammal turnover at the boundaries between the Lower and Middle Aragonian and the Middle and Upper Aragonian, respectively. Our results support the existence of a selective turnover during the Aragonian and Lower Vallesian., [FR] Ce travail actualise la taxonomie et la distribution faunique du registre fossile des petits mammifères du bassin de Calatayud-Montalbán de l’Aragonien au Vallésien inférieur. Les ordres Rodentia, Eulipothyphla et Lagomorpha sont inclus dans l’étude. Le modèle de renouvellement faunique est analysé et expliqué en relation avec les changements climatiques globaux. Sept événements fauniques principaux ont été reconnus et corrélés aux changements climatiques majeurs, grâce aux enregistrements isotopiques marins (oxygène et carbone). Les événements δ18O Mi-2 et Mi-3 sont significativement corrélés aux renouvellements fauniques qui touchent les micromammifères, respectivement aux limites de l’Aragonien inférieur/moyen et moyen/terminal. La présente analyse corrobore l’existence d’un renouvellement faunique sélectif au cours de l’Aragonien et du Vallésien inférieur., The Spanish MICINN/MINECO projects CGL2004-02094/BTE, CGL2007- 65208, CGL2008-04200/BTE; CGL2011-28877 support this study.

[ES] Se da a conocer una nueva sección que incluye nueve yacimientos de microvertebrados en superposición estratigráfica en la Cuenca de Calatayud-Montalbán (España). Se describen las localidades de la sección de la Cañada y sus faunas de micromamíferos, lo que posibilita su correlación con el Vallesiense inferior de la cercana sección de Nombrevilla. Los resultados obtenidos en este trabajo son importantes debido a que ayudan a mejorar la resolución temporal del registro faunístico del Vallesiense inferior del área de Daroca, y a precisar su posición bioestratigráfica relativa. Por otra parte, el tramo superior de la sección de la Cañada incluye dos faunas del Turoliense que incrementan el escaso conocimiento del registro de esta edad en la Cuenca de Calatayud-Montalbán., [EN] A new section including nine stratigraphically superposed microvertebrate fossil localities from the Calatayud-Montalbán basin (Spain) is presented. The Cañada localities and the small mammal assemblages are described, allowing a biostratigraphical correlation with the lower Vallesian from the nearby section of Nombrevilla. The results of this work are important because they help to improve the time resolution of the lower Vallesian faunal record from the Daroca area and to precise their relative biostratigraphical position. In addition, the upper part of the Cañada section includes two Turolian faunas, increasing the poor record from this age in the Calatayud-Montalbán basin.

Since the proposition in 1975 of the European Neogene Mammal (MN) scale by Pierre Mein, the amount of taxonomical, stratigraphical and chronological information around Europe has increased exponentially. In this paper, the stratigraphical schemes of three of the best studied areas for the Lower and Middle Miocene, the Aragonian type area in Spain and the Upper Freshwater Molasse from the North Alpine Foreland Basin in Switzerland and Bavaria, are compared. The correlation of their local biostratigraphies are discussed. Sixteen rodent’s events are studied and ranked in the three areas according to their local biostratigraphy. This study shows, and quantifies for the first time, the significant asynchronies of the different included rodent events. The MN-system is discussed in the light of those results. In accordance, we propose that it is still useful but only in a biochronological way, as a sequence of time-ordered reference localities allowing coarse long-distance correlations. In order to obtain better temporal resolution, this system has to be combined with local biostratigraphies that are well calibrated to the time scale, implementing the information about synchrony and diachrony of mammal events in different areas.

Received: 21 January 2015 /Revised: 9 March 2015 /Accepted: 27 April 2015 /Published online: 10 June 2015, © 2015, Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg. At the time of its discovery, over 25 years ago, the Greek locality of Aliveri preserved the easternmost occurrence for the early Miocene of cricetodontine hamsters such as Cricetodon, Megacricetodon and Democricetodon. As knowledge on the early Miocene history of the eastern Mediterranean increased, the faunal composition became more enigmatic, because of the presence of typical European elements (Pseudotheridomys, Heterosorex, Plesiodimylus, Myxomygale), absent from Anatolia. Recently, the ungulates from the locality were rediscovered, expanding the faunal list with the equid Anchitherium and the pecorans Lagomeryx (two species), Eotragus and Palaeomerycidae gen. et sp. indet. In this paper, we examine the fauna of Aliveri in the light of the current state of knowledge. The assemblage is typical for MN 4, but is believed to pre-date European localities of that biochronological unit. Similarity with Anatolian MN 3 localities suggests that the origin of the fauna lies mostly in that region, whereas the major differences with European localities suggest relative isolation, in line with palaeogeographic reconstructions of the period. However, when isolation was lifted, a number of European elements were added to the local fauna, but, presumably because of an ecological barrier, did not move further into Anatolia. Migrations at the onset of MN 4 can explain the composition of the Greek fauna, but we are still far from completely understanding the complex history of the eastern Mediterranean during the early Miocene., This research was supported by the Spanish MINECO Project No. CGL2011-28877 and the research group UCM 910607. The work of A.O. was supported by a FPU Predoctoral Fellowship and a SYNTHESYS grant at NL-TAF, and the work of .H.-B. by a FPI predoctoral Fellowship.

© 2015, Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg. Morphometrical studies were carried out on the dental material of Democricetodon from the Calatayud-Montalbán Basin. Principal component analyses were incorporated into the analyses to reduce the number of metrical and morphological variables. Morphological variability was studied as the morphological distribution of character states, based on multivariate statistics, and plotted against time. The results of these analyses indicate that increased dental size is significantly correlated to the dental morphological value in the two Democricetodon lineages studied. We found that the rates of change in variables are not linear and that periods of higher rates can be correlated with global climatic changes. In addition, morphological variability is significantly correlated with relative abundances of the studied taxa. High morphological variability, as a proxy of niche breadth, may result from increased intraspecific interferences or from the relaxation of interspecific interactions caused by a decrease in primary productivity., This research was supported by the MICIIN and MINECO, Projects CGL-2008-04200/BTE and CGL2011-28877.

[EN] As a consequence of the growth of the Antarctic ice-sheet during the middle Miocene, a global decrease of temperatures and an associated increase in aridity provoked several environmental changes all around the world. Such environmental variations can be detected in the continental record of the mammalian prey community structure using a synecological approach. Because of the good quality of its faunas, the rich Aragonian vertebrate fossil record from the Madrid Basin (Spain) appears as a good candidate to explore these environmental changes. In order to analyse the climatic evolution of the Iberian Peninsula associated to the Global Cooling Event, two classic palaeosynecological methodologies (cenograms and body size diversity), based on body-size community structure, were applied to 6 fossil sites from the Madrid Basin, ranging over 2 million years (15.5 ¿ 13.5 Ma). To establish a comparative framework, we used the ecological faunal data from 100 modern localities uniformly distributed all around the world. Our palaeoenvironmental inference is based on multivariate discriminant analysis of the dataset containing both modern and fossil mammals. Finally, we can conclude that the Aragonian mammalian assemblage from the Madrid Basin showed a predominance of semiarid environments with pulses of higher aridity in biozones Dc, E and F associated with the Global Cooling Event of the middle Miocene., [ES] Como consecuencia del crecimiento del casquete polar Antártico, durante el Mioceno medio, se produjo un descenso global de la temperatura asociado a un aumento de la aridez. Este tipo de cambios ambientales pueden ser detectados en el registro continental, siguiendo un modelo sinecológico para analizar la estructura de las comunidades de las faunas de mamíferos herbívoros. Debido a la calidad de sus faunas, el registro fósil de las faunas de vertebrados del Aragoniense de la Cuenca de Madrid se antoja como un buen candidato para explorar estos patrones de cambio ambiental. Con el objetivo de analizar la evolución climática de la Península Ibérica asociada al evento de enfriamiento global durante este lapso temporal, dos metodologías paleosinecológicas clásicas (cenogramas y espectros de diversidad de tamaño corporal), basadas en la estructura de tamaños corporales de las comunidades de mamíferos, han sido aplicadas a la fauna de herbívoros fósiles presente en seis yacimientos de la Cuenca de Madrid, abarcando aproximadamente 2 millones de años (15.5 – 13.5 Ma). Se ha establecido un marco comparativo usando los datos ecológicos de la fauna de mamíferos presente en 100 localidades uniformemente distribuidas por todo el planeta. Esta inferencia paleoambiental está basada en la aplicación de análisis discriminante multivariante sobre el conjunto de datos de las faunas actuales y fósiles. Finalmente, las faunas de mamíferos del Aragoniense de la Comunidad de Madrid mostraron una predominancia de ambientes semiáridos con varios pulsos de mayor aridez en las biozonas Dc, E y F asociados al evento de enfriamiento global del Mioceno medio.

[EN] In the present study we analyze the microwear of the species included in the lineage Armantomys aragonensis-A. tricristatus of two samples from two middle Miocene localities from the Madrid Basin (El Cañaveral and Casa Montero). The methodological part of the study compares light stereomicroscope photographs from resin casts and Environmental Scanning Electron Microscope (ESEM) photographs from original material. Furthermore two regions of the tooth crown (the most lingual part of the anteroloph, and the most lingual part of the protoloph) and two homologous regions of first and second upper molars have been analyzed. The paleoecological part includes the results of the microwear analyses of the two species included in the lineage A. aragonensis-A. tricristatus. The replacement of A. aragonensis with A. tricristatus in the Madrid Basin occurred during the Middle Miocene Climate Transition (MMCT) and is marked by a change in dental morphology. Therefore, in order to infer changes in diet associated to a shift in the environment, we checked for correlations on microwear features between the two different morphologies of the species. The two methodologies tested, ESEM on original teeth and light stereomicroscopy on resin casts, showed similar results on microwear analysis in the glirid Armantomys. Besides, both regions of the tooth crown and dental elements showed the same microwear patterns. The substitution of the species included in the lineage Armantomys aragonensis-A. tricristatus might not imply a change in diet., [ES] En el presente trabajo analizamos los patrones de microdesgaste de las especies incluidas en el linaje Armantomys aragonensis-A. tricristatus de dos muestras procedentes de dos yacimientos del Mioceno medio de la Cuenca de Madrid (El Cañaveral y Casa Montero). En la parte metodológica de este estudio se comparan fotografías de lupa binocular obtenidas a partir de moldes de resina y fotografías de microscopio electrónico de barrido ambiental (ESEM) a partir de material original. Además, se han analizado dos regiones de la corona dental (la zona más lingual del anterolofo y la zona más lingual del protolofo) y dos regiones homólogas del primer y segundo molar superiores. La parte paleoecológica del estudio incluye los resultados de los análisis de microdesgaste de las dos especies incluidas en el linaje A. aragonensis-A. tricristatus. El reemplazamiento de A. aragonensis por A. tricristatus en la Cuenca de Madrid tiene lugar durante la Transición Climática del Mioceno Medio (MMCT) y está marcado por un cambio en la morfología dental. Así, para inferir variaciones en la dieta asociados a un cambio en el ambiente, hemos estudiado la correlación de los patrones de microdesgaste entre las dos diferentes morfologías que presenta cada especie. Las dos metodologías comparadas, ESEM en dientes originales y lupa binocular en moldes de resina, muestran resultados similares en los análisis del microdesgaste en el glírido Armantomys. Además, dos regiones de la corona dental y los dos elementos dentales muestran los mismos patrones de microdesgaste. La sustitución de las especies incluidas en el linaje Armantomys aragonensis-A. tricristatus podría no ir asociado a un cambio en la dieta.