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Geometric morphometric allows characterizing complex morphologies in order to quantify the geometry of the structure and facilitate comparisons. It allows performing methods analysing differentiation pattern based on variance, such as the Principal Component Analysis (PCA). For that reason, it has been chosen as the method to analyse the mandibles of two extinct species of cricetids rodents: Cricetodon aff. aureus and Megacricetodon minor from the MN6, middle Miocene from Goldberg and Steinberg (Germany). We performed a digitisation of 18 landmarks that resumes the most relevant characteristics of these mandibles. We also performed a measure of the mechanical advantage and potential of the mandibles. In that way, we have been able to quantify notorious morphological differences on the angular and condylar processes and the lower masseter insertion and establish significant differences among the biomechanical behaviour of the mandibles. Later, we can relate the morphological and biomechanical information with speed and force biting.

Mortality curves of extinct rodents can be reconstructed by using relative wear calculated from the amount of dentine exposed. MicroCT scanning of molars of the extinct Eomyid genus Ligerimys shows that this Wear Index increases gradually with wear; this means that wear classes can serve as a proxy for age and can therefore be used to reconstruct mortality curves. We reconstructed mortality curves of three species of Ligerimys from the late early Miocene of Spain. These curves show a similar trend, with decreasing numbers of molars as the amount of wear in each class increases. The curves show remarkable similarities to those of the wood mouse Apodemus. This suggests that Ligerimys was, like Apodemus, at the fast end of the fast-slow continuum, in other words r-selected, though not as extreme as some other rodents., This work was supported by the European Union [SYNTHESYS project, grant ES-TAF-1084]; Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación; FEDER/ European Union [PGC2018-094122-B-I00].

This work is included on the research framework of the Investigation Group UCM-910607 and as part of research project CGL2015-68333-P (MNCN, CSIC).

The small mammal assemblages from Alto de Ballester 1 and 2 in the Rubielos de Mora basin represent a unique faunal assemblage from the late early Miocene (Ramblian, MN 3). Together, the assemblages yielded five species of rodents (Peridyromys murinus, P. aff. murinus, P. aquatilis, Pseudotheridomys aff. fejfari and cf. Steneofiber depereti), and nine insectivores (Galericinae indet., Desmanella fejfari, Myxomygale minor, Desmanodon daamsi, Chainodus cf. sulcatus, Heterosorex sp., cf. Oligosorex thauensis, cf. Clapasorex alvarezae, and Paenelimnoecus cf. truyolsi). High abundance and diversity of insectivores, and the presence of a beaver and a dimylid show that the assemblages represent a humid, forested environment. This is in line with the palaeobotanical evidence of the basin. The two Alto de Ballester assemblages, which are very different from other Ramblian faunas, show that there was a variety of ecosystems on the Iberian Peninsula at this period, probably drier in the inland and more humid near the coastal zone.

[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.

This study has been partly funded by research projects CGL2008-05813-CO2-01, (MICIIN, Spanish Government), CGL2007-65208, CGL2008-04200/BTE and Research Group UCM 910607. R. L. A. is currently supported by the Ramon y Cajal Program. I. G.-P. has a postdoctoral contract with the Spanish Foundation for Science and Technology (FECYT) and the Spanish Ministry of Science and Innovation.

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 ende...

A new genus of Gliridae, Simplomys gen. nov. is proposed. It contains glirids with a simplified dental pattern from the European Early and Middle Miocene. Simplomys gen. nov. includes several species originally described as Pseudodryomys such as Simplomys simplicidens, Simplomys robustus, Simplomys julii, and Simplomys aljaphi. In addition, a new species, Simplomys meulenorum sp. nov., is proposed from the Spanish Miocene. The species of this genus share not only a very reduced and simplified dental morphology, but also unique dental proportions that clearly separate them from any other genera of Gliridae. Simplomys gen. nov. is recorded in most of the fossil faunas from the Early and Middle Miocene of the Iberian Peninsula, and shows the maximum diversity in this area during Mammal Neogene Zones MN 3 and MN 4. The genus has been also recorded in other European countries such as France, Germany, and Switzerland, conferring to this very characteristic taxon an important role for biochronological correlations within the European continent. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 157, 622–652.

The results of our study on the record of the tribe Cricetodontini (Cricetidae, Rodentia, Mammalia) from the European latest middle Miocene (Calatayud-Daroca and Valles-Penedes basins from Spain, several fissure fillings from France and several basins and karstic sites from central and eastern Europe) is presented here. We have analysed the morphological and diversity patterns of the Cricetodontini and compared them with those described in the Calatayud-Daroca Basin in order to evaluate the presence of a general pattern of the tribe on a European scale. Our findings show the presence of a high diversity of Cricetodontini during the late Aragonian (13.80–10.77 Ma) in all of the areas studied in Europe to date, and that this period of high diversity followed an interval of low diversity of species with basal morphology. The Cricetodontini shows a high morphological diversity during the late Aragonian, and the species present different combinations of features as well as a high degree of endemicity. These results are in accordance with the evolutionary patterns recently described from the Spanish Calatayud-Daroca Basin. The late Aragonian, throughout all of Europe, represents a dramatic and important interval for the evolutionary history of the Cricetodontini.

Deep-time perspectives in macroecology are essential with regard to understanding the impact of climate forcing on faunal communities. Using late Miocene rodent faunas (12 to 5 Ma) from two different biogeographical provinces from southwestern Europe, we asked whether the waxing and waning of faunas with dissimilar ecological affinities tracked climate in different ways. The latest middle Miocene featured a fauna dominated by dormice with forest and mixed-habitat affinities. This group declined towards the Upper Miocene. Rodent taxa with the highest values of richness at the beginning of the Upper Miocene are generalists in the southern province and specialists of forested habitats in the northern province. Finally, we identified a third, increasingly significant group of rodents linked to open landscapes towards the end of the Miocene. These three broad ecological groups showed differential responses to a complex set of interconnected circumstances, including the biogeographic structure of the study area and climatic changes throughout time.

Murine rodents represent a highly diverse group, which displays great ecological versatility. In the present paper we analyse the relationship between dental morphology, on one hand, using geometric morphometrics based upon the outline of first upper molar and the dietary preference of extant murine genera, on the other. This ecomorphological study of extant murine rodents demonstrates that dietary groups can be distinguished with the use of a quantitative geometric morphometric approach based on first upper molar outline. A discriminant analysis of the geometric morphometric variables of the first upper molars enables us to infer the dietary preferences of extinct murine genera from the Iberian Peninsula. Most of the extinct genera were omnivore; only Stephanomys showed a pattern of dental morphology alike that of the herbivore genera.

The oldest record of Cricetodon (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 to Cricetodon 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 of C. soriae until now. New complete descriptions of the type material from SOMN and an emended diagnosis of C. soriae are presented. Comparisons with all the species of Cricetodon described to date have been made. Differences between Cricetodon aureus and Cricetodon meini are 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 of C. aureus and C. meini, and to compare them both with C. soriae. The presence of common characteristics indicates a closer relationship of C. soriae with the species of Cricetodon from Asia Minor than with the first representatives of Cricetodon in central and eastern Europe. The distribution of C. soriae in the Iberian Peninsula is coincident with the global cooling event and the increasing in aridity in southwestern Europe, and the faunal dispersion event called Conohyus/Pliopitechus that took place during the local biozone E. © 2013 by the Society of Vertebrate Paleontology., We acknowledge financial support by the Spanish MICINN to projects CGL2004-02094/BTE, CGL2007-65208, CGL2008-04200/BTE, and CGL 2011-28877 (MICINN/MINECO). I.G.-P. acknowledges a JAE-Doc contract (CSIC program ‘Junta para la Ampliación de Estudios’), co-funded by the European Social Fund, and P.L.-G. acknowledges a UCM Predoctoral contract. This research is a contribution by the research group UCM-BSCH-910607 on Evolution of Cenozoic Mammals and Continental Palaeoenvironments

Mammals are among the fastest-radiating groups, being characterized by a mean species lifespan of the order of 2.5 million years (Myr)1,2. The basis for this characteristic timescale of origination, extinction and turnover is not well understood. Various studies have invoked climate change to explain mammalian species turnover3,4, but other studies have either challenged or only partly confirmed the climate–turnover hypothesis5–7. Here we use an exceptionally long (24.5–2.5Myr ago), dense, and welldated terrestrial record of rodent lineages from central Spain, and show the existence of turnover cycles with periods of 2.4–2.5 and 1.0Myr. We link these cycles to low-frequency modulations of Milankovitch oscillations8, and show that pulses of turnover occur at minima of the 2.37-Myr eccentricity cycle and nodes of the 1.2-Myr obliquity cycle. Because obliquity nodes and eccentricity minima are associated with ice sheet expansion and cooling and affect regional precipitation, we infer that long-period astronomical climate forcing is a major determinant of species turnover in small mammals and probably other groups as well.