The Aragonian and Vallesian high-resolution micromammal succession from the Calatayud-Montalbán Basin (Aragón, Spain)

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 showsseven major faunal events,which are correlated to major climate changes based on marine stable oxygen and carbon isotope records. The episodesδ 18OMi-2 and Mi-3 are significantly correlated with major micromammal turnover at the boundaries between lower and middle Aragonian and middle and upper Aragonian, respectively. Our resultssupport the existence of a selective turnover during the Aragonian and lower Vallesian

Updated biochronology of the Madrid Basin: species distribution and implications for the Middle Miocene rodent faunas of Spain

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

Impact of global climate in the diversity patterns of middle Miocene rodents from the Madrid Basin (Spain)

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.Peer Reviewe

Diseño de una propuesta didáctica en 2º Bachillerato para el aprendizaje de los recursos minerales y energéticos en periodo de confinamiento

En este trabajo se presenta el diseño de una propuesta didáctica para la materia de Geología para un aula de 2º de Bachillerato. Más específicamente, la propuesta se ha diseñado para el bloque 8 del currículo de esta materia en Aragón (“Recursos minerales y energéticos y aguas subterráneas”, según Orden ECD/494/2016, de 26 de mayo), en concreto para la parte de los recursos minerales y energéticos. La propuesta didáctica aquí presentada representa una adaptación a la desarrollada durante el Practicum II. Ha sido diseñada para implementarse en periodo de confinamiento, de modo que los alumnos deben desarrollarla desde sus casas con las orientaciones del docente y tienen por tanto la necesidad de disponer de un dispositivo electrónico (ordenador o tablet) y de conexión a internet.<br /

Preliminary study of the rodent fauna of the Miocene fossil site of El Cañaveral (Madrid, Spain)

5 páginas, 3 figuras.-- Trabajo presentado al VIII Encuentro de Jóvenes Investigadores en Paleontología.[EN]: This work shows the results of the preliminary study of the rodent faunas from the Miocene fossil site of El Cañaveral. This site is compared with other localities from the Madrid Basin of similar age. The morphometric study of the rodent assemblage from El Cañaveral allows us to correlate this site with the local biozone E (Middle Aragonian, Middle Miocene, MN5). Our results indicate that the age of this site is close to the oldest localities of the biozone E.[ES]: En este trabajo se dan a conocer los resultados del estudio preliminar de la fauna de roedores del yacimiento mioceno de El Cañaveral. Este yacimiento se compara con otros yacimientos de edad similar de la Cuenca de Madrid. El estudio morfométrico de la asociación de roedores encontrada, nos ha permitido datar el yacimiento dentro de la biozona local E (Aragoniense medio, Mioceno medio, MN5). Nuestros resultados indican una edad cercana a los yacimientos más antiguos de dicha biozona.Este trabajo ha sido financiado por el proyecto CGL-2008-04200/BTE del MICIIN y el grupo de investigación UCM-910607. VH-B disfruta de una beca predoctoral FPI. AO disfruta de una beca predoctoral FPU. IG-P ha disfrutado de un contrato postdoctoral del MICIIN y la FECYT.Peer reviewe

New approaches to examining and interpreting patterns of dental morphological variability in Miocene cricetids

© 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.Peer Reviewe

Comparison of Miocene Xerini (Sciuridae, Mammalia) from Central Spain and Germany

Poster presented in: Neogene to Quaternary geological evolution of Mediterranean, Parathethys and Black Sea. 14th Congress, 8-12 September 2013 Istanbul, Turkey, RCMNS (Regional Committee en Mediterranean Neogene Stratigraphy)Despite the extensive record of sciurids of the tribe Xerini from Miocene European localities, few have been the works that have tried to present an overview of his group at continental scale (Cuenca Bescos, 1988; De Bruijn, 1999; Aguilar, 2002). The xerini squirrels have a characteristic dental morphology that can be easily recognized by mammal paleontologist. The few species described within this tribe show a very similar dental morphology and the diagnostic characters for the diverese genus are in most cases mino differences, due to the maintenance of primitive dental patterns. This characteristic, and rather conservative, morphology has promoted in our opinion, an oversimplified taxonomy. This is specially evident on the genus Hetereoxerus Stehlin & Schaub, 1951, with a temporal distribution of around 20 My, and only six species described (De Bruijn, 1999). This work shows a morphological comparison between the xerine record of central Spain and Germany. Most of the materials recorded from these areas have been assigned to Heteroxerus rubricati, H. Huerzeleri and H. grivensis (Cuenca Bescos, 1988; Ziegler & Fahlbush, 1986; Ziegler, 2005). The comparison has demonstrated the existence of constant morphological differences between the ground squirrels from these two areas. This result shows the existence of taxonomical differences, not indicated by previous authors, and points out the need for a revision of this tribe in order to have a better understanding of its evolution and paleobiogeography. This result also reinforces the idea of a strong bioprovincialism during most part of the Miocene postulated on the basis of other mammal groups.SYNTHESYS Project (ES-TAF-2742), financed by the European Community Research Infrastructure Action under the FP6 "Structuring the European Research Area" Programme.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.Peer reviewe

First faunal insights from biozone Db (middle Miocene, middle Aragonian) of the Madrid Basin (Spain)

[Purpose]: Palaeontological excavations following public works around the Manzanares River in the metropolitan area of Madrid yielded new small mammal fossil remains from two locations. We present here a description of their rodent assemblages, and a biostratigraphical and palaeoecological context of them. A comparison of these levels to the contemporaneous fossil localities of the Calatayud-Montalbán Basin and to other middle Aragonian sites from Madrid is also shown.[Material]: A total of 371 dental elements have been studied from the five levels of the two locations (Puente de Praga site and Madrid Río2 site).[Results]: The rodent associations from the five new levels are similar and comprise eight taxa: Megacricetodon primitivus, Megacricetodon vandermeuleni, Democricetodon moralesi, Democricetodon sp., Armantomys aragonensis, Microdyromys koenigswaldi, Pseudodryomys ibericus and Heteroxerus rubricati. It represents a low equitable rodent community characterized by the predominance of the genus Megacricetodon and a poorly-represented fauna of glirids and sciurids.[Conclusions]: The fossil association and its biostratigraphical markers indicate a correlation of the levels to the upper part of biozone Db, this being the first time that the rodent assemblages of this biozone are described in the Madrid Basin. Based on the rodent content we suggest more humid or/and more closed environments in biozone Db than in biozones Dc and Dd. The Calatayud-Montalbán record shows more diverse rodent assemblages in biozone Db, with taxa not recorded in Madrid that are indicative of more humid or structured environments. Therefore, the Madrid associations would represent dryer or/and more open environments than the Calatayud-Montalbán associations.This work was supported by the Spanish MICINN projects CGL-2008-04200/BTE and CGL2011-28877. VH-B was supported by a FPI pre-doctoral fellowship.Peer Reviewe

Aliveri revisited, a biogeographical appraisal of the early Miocene mammals from the eastern Mediterranean

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.Peer Reviewe