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[EN] 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 includes 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., [ES] La morfometría geométrica permite caracterizar formas completas para cuantificar la geometría de la estructura y facilitar las comparaciones. Permite llevar a cabo metodologías que analizan esos patrones de diferenciación como el Análisis de Componentes Principales (ACP), a través del cual se estudia la varianza de una manera simple. Por esta razón ha sido el método elegido para analizar las mandíbulas de dos especies extintas de cricétidos: Cricetodon aff. aureus y Megacricetodon minor de la MN6, Mioceno medio de los yacimientos de Goldberg y Steinberg (Alemania). Hemos llevado a cabo la digitalización de 18 puntos de referencia (landmarks) que resumen las características más relevantes de las mandíbulas. Además hemos realizado la medición de las ventajas y potencias mecánicas de estas. De esta manera, hemos podido cuantificar diferencias morfológicas notorias en los procesos angular y condilar y en la inserción del masetero inferior y establecer diferencias significativas entre los comportamientos biomecánicos de las mandíbulas para después relacionarlo con la velocidad y la fuerza de la mordida de estos roedores., This is a contribution of the Research Group Team 910607 on Evolution of Cenozoic Mammals and Continental Palaeoenvironments of the Complutense University of Madrid. This study was also supported by the Spanish Economy and Competitiveness Ministry research project PGC2018 094955-A-100 and PGC2018-094122-B-100.

Here, we describe new specimens of the cricetid Hispanomys moralesi López-Antoñanzas et al. 2010, found in Batallones 4 site, which belongs to Cerro de los Batallones assemblage (Upper Vallesian, Upper Miocene). Previously, metrical and morphological data of H. moralesi have been used to proof whether the different sites within the butte were filled simultaneously or there was a time span among them (López-Antoñanzas et al. in Zool J Linnean Soc 160(4):725–747, 2010). 129 isolated molars, nine lower jaws, ten maxilla fragments and four skull remains from Batallones 4 were identified as H. moralesi and were included in the study. Length and width data were also taken on the dental pieces. This information has been used to perform a biometrical and morphological study, in order to compare the specimens of Batallones 4 with the rest of sites within the butte and with other Hispanomys species. The evolutionary stage of the fossils from Batallones 4 indicates that they are slightly more modern than the specimens from Batallones 10, and also have more primitive features than the ones from Batallones 1, 3 and 5. This information support the hypothesis by López-Antoñanzas et al. (2010): the cavities were not filled synchronously, but one after the other, beginning with southerner side of the butte (Batallones 10) and progressing towards north, being Batallones3 the last one to fill and, consequently, the youngest locality. The results remark the potential use of H. moralesi as a tool which can be used as a biochronological indicator that help us to relatively date a set of fossil sites., 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).

Trabajo presentado en II Joint Congress on Evolutionary Biology (Evolution), celebrado en Montpellier (Francia), del 19 al 22 de agosto de 2018, With a diversity approaching 300 species, squirrels inhabit all the world's biomes and almost all the continents (except Antarctica and Australia), which makes them an exceptional group for studying ecological preferences evolution. Therefore, we tested one of the predictions of the resource-use hypothesis proposed by E.S. Vrba, which foretells that generalist species have lower diversification rates than specialist species, on 229 species of Sciuridae (Rodentia, Mammalia). We compared speciation rates between biome specialists (stenobiomic species) and biome generalists (eurybiomic species) using the biomic specialization index (BSI), which is based on the number of biomes occupied by each species. Furthermore, we performed an ancestral reconstruction of biomic specialization in a calibrated phylogenetic tree. Our results are consistent with the predictions of the resource-use hypothesis, which foretells a higher speciation rate of lineages restricted to a single biome (BSI = 1) than lineages which occupied several biomes (generalists, 1

Trabajo presentado en el 5th International Palaeontological Congress, celebrado en París (Francia) del 9 al 13 de julio de 2018, With a current diversity approaching 300 species, squirrels have conquered all the world’s biomes and almost all the continents (except Antarctica and Australia) since their origin in the Eocene, which makes them an exceptional group for studying ecological preferences evolution. Therefore, we performed a multifossil-calibrated phylogenetic tree including 229 species of Sciuridae (Rodentia, Mammalia) and we calculated the diversification rates. Then, we tested one of the predictions of the resource-use hypothesis proposed by E.S. Vrba, which foretells that generalist species have lower diversification rates than specialist species due to a better adaptive capacity during an environmental change episode. We compared speciation rates between biome specialists (stenobiomic species) and biome generalists (eurybiomic species) using a Multiple State ’Speciation’ and Extinction model (”MuSSE”) in R. We considered three groups relaying on the biomic specialization index (BSI), which is based on the number of biomes occupied by each species: specialists (BSI = 1), generalists (BSI between 1 and 5) and extreme generalists (BSI≥5). Furthermore, we performed an ancestral reconstruction of biomic specialization in the phylogenetic tree. Our results are consistent with the predictions of the resource-use hypothesis, which predicts a higher speciation rate of lineages restricted to a single biome (specialists) than lineages which occupied several biomes (generalists). Additionally, we found that the biomes with higher proportions of specialist species are the tropical rainforest (I) with around 36% of species restricted to this biome and the steppes and cold-deserts (VII) in which inhabit 24 stenobiomic species (32.4%). This is also congruent with the resource-use hypothesis, which predicts higher specialization of species inhabiting biomes that underwent a high degree of fragmentation and contraction associated to global climatic changes; while rainforest distribution is very fragmented during glacial maxima, steppes are more affected by interglacial maxima.

Trabajo presentado en el II Iberian Symposium on Geometric Morphometrics, celebrado en Madrid (España, del 8 al 10 de junio de 2016, Cricetodon and Hispanomys (Rodentia, Mammalia) include several species that illustrate the mosaic evolution. Therefore, the generic assignation of some of these species is controversial. Agustí, (1982) remarked that Ruscinomys and some species of Hispanomys present trilobed contour, whereas Cricetodon has it straight. Also, López-Guerrero et al. (2015) suggest the contour of the anterior upper molars (M1) as a discriminatory generic character. The contour can be studied by using the Fourier method. We applied Fourier method on the photographs of 56 M1s belonging to Cricetodon meini from VieuxCollonges (middle Aragonian, middle Miocene) and Hispanomys aragonensis from Pedregueras 2A, 2C, 1C and Nombrevilla 14 (early Vallesian, late Miocene). These species were used as a case study because there is no doubt in their generic assignation and they present very different contours: straight―Cricetodon—and trilobed— Hispanomys―. Our aim is to study whether the differences that are observed in the M1 contour between these two species could be statistically tested. Using Fourier methodology, we have performed a Principal Component, a cluster and a discriminant analyses. The results show differences between the two species. The PCA reveals two distinct groups that correspond to the two species. Furthermore, the cluster analysis also reveals two large, distinct groups. Finally, the discriminant analysis supports the results above with a significant pvalue

Trabajo presentado en el 1st International Meeting of Early-stage Researchers in Palaeontology - XIV Encuentro de Jóvenes Investigadores en Paleontología: New perspectives on the Evolution of Phanerozoic Biotas and Ecosystems, celebrado en Alpuente, Valencia (España), del 13 al 16 de abril de 2016, The tribe Cricetodontini is an extinct group of medium-sized cricetid rodents commonly found in Miocene basins in Europe, Asia and Asia Minor. This group has not been traditionally used for local biostratigraphy, but recent studies have shown its significance as biostratigraphic indicators in the Calatayud-Daroca and other European Miocene basins (López-Guerrero et al., 2015). The most wellknown and up-to-date record of this group in the Iberian Peninsula is that from Calatayud-Daroca and Vallès-Penedès basins (López-Guerrero et al., 2015, and references included). Several localities in the central sector of the Duero Basin have also yielded fossils of Cricetodontini (García Moreno, 1987); which were recently reviewed (Castillo Marzo, 2014). This work reviews the material from three localities of the Duero Basin (Tiedra 1, Tordehumos 1 and Ampudia 9). The morphology of the specimens was described and discussed and their taxonomy is now well resolved (Castillo Marzo, 2014), so here we focus in the biostratigraphic correlation of some of the studied sites. The presence of Hispanomys nombrevillae among other rodents correlates Tordehumos1 and Tiedra1 to local biozone H of the Calatayud-Daroca Basin (uppermost MN7/8-MN9, upper Aragonian/lower Vallesian, middle/upper Miocene), being the first record of this species in the Duero Basin. The presence of Hispanomys aragonensis in Ampudia 9 is congruent with a correlation to local biozone I of the same basin (MN9, upper Vallesian, upper Miocene), also representing the first record of the species in the basin. Our results update the biostratigraphic correlation of Ampudia9 and emplaces Tordehumos1 and Tiedra1 for the first time. At the same time highlight the broader distribution areas of some Iberian species of Hispanomys. This paleobiogeographic situation evidence the similarity between the Duero Basin and the other Iberian Miocene basins, suggesting a closer relationship than previously thought.

Trabajo presentado en el 1st International Meeting of Early-stage Researchers in Palaeontology - XIV Encuentro de Jóvenes Investigadores en Paleontología: New perspectives on the Evolution of Phanerozoic Biotas and Ecosystems, celebrado en Alpuente, Valencia (España), del 13 al 16 de abril de 2016, The Pliocene site of Layna is a karst filling in the Iberian System (López Martínez, 1989) placed on the northern edge of the Tagus Basin. Its outstanding abundance of mandibles and maxillas makes Layna a good test-case locality to apply statistical methods in studies of fossil assemblages, minimizing the possible biases present in poorer sites. The objective of this work is to analyze the wearing of the different molar elements, taking for the first time an approach that can study this issue in teeth from the same individual. We chose Stephanomys donnezani (Depéret, 1890) because it is one of the most abundant taxa in Layna. We followed the method proposed by Freudenthal et al. (2002) which described the Wear Index (WI) as the ratio between exposed dentin surface and the total occlusal surface of the molar. We took photographs and digitized the occlusal surface of 167 molars, calculating the area of the 2D projection of the occlusal surface and the exposed dentine in pixels using Adobe Photoshop CS4 software. Molar wearing was compared among the different elements by means of Spearman correlation of percentage histograms as well as by Mann-Whitney U tests. Linear regression analyses were used to evaluate differences in wear among elements of the same dental row. Molars were considered to have same wear rate when slopes of those regressions ranged between 0.9 and 1.2. The results of the Spearman correlations and Mann-Whitney U tests indicate that most of the elements showed similar wearing levels. Nevertheless, when studying teeth from the same individual, althoughthere were no significative differences between m1 and m2 (slope=1.006,r2=0.744,p

This paper contains formal definitions of the Early to Middle Aragonian (late Early–Middle Miocene) smallmammal biozones from the Aragonian type area in North Central Spain. The stratigraphical schemes of two 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, have been compared. This comparison allows the analysis of the order of shared mammal events in the two countries, and the quantification of the resulting asynchronies based on their temporal correlations. The order of the events is very similar in Spain and Switzerland. In order to estimate the diachrony, two age-model options are used for the Swiss record. Our preferred option yields no discrepancies with SW European paleomagnetic and radiometric calibrations of the Ramblian and Early Aragonian bioevents. All Swiss first taxa occurrences precede those in the Aragonian type area by 0.74Myr on average. The asynchronies (1-2Myr) of the species arriving in the late Middle to early Late Aragonian may be higher than in the Early Aragonian (0-1Myr). The implications for the biochronological mammal Neogene system are discussed. Evidence is given confirming the unfeasibility of a formal European biozonation, since it is realised, that 1) most indicator species and many genera of rodents yielding the most detailed zonations have limited geographical ranges hampering recognition of the mammal Neogene zones; and 2) first and last taxon occurrences are diachronical. Therefore, the mammal Neogene system based on a sequence of time-ordered reference localities is preferred to the one based on selected bioevents “developed in widespread geographic areas”.

Comunicación presentada al 10th Annual Meeting of the European Association of Vertebrate Palaeontologists, celebrado en Teruel, Spain, 19-24 June 2012., The Cerro de los Batallones fossil sites, Upper Miocene (MN10), are located in the south of the province of Madrid (Spain). Batallones-1 and Batallones-3 have an unusually high proportion of fossil carnivores (over 98.5% of the remains determined as mammals are carnivores) and both localities have been interpreted as carnivore traps. The Batallones-3 carnivores association comprises two amphicionids (Magericyon sp and Thaumastocyon sp), one ursid (Indarctos sp), three felids (Machairodus aphanistus, Promegantereon ogygia and Styriofelis vallesiensis), one hyenid (Protictitherium crasum) and five musteloids (Eomellivora piveteaui, Martes sp, Proputorius sp, Mephitinae indet and Mustelidae indet). The aim of the present paper is to study the systematics of the fossil of Eomellivora from Batallones-3, as well as to describe the complete skull preserved from Batallones-3 by means of a virtual 3D model.

Material of Hispanomys (Rodentia, Cricetodontinae) is described from various localities at Batallones (MN10) (Madrid, Spain). All of it belongs to a single species, which differs from the other known species of the genus and a new taxon, Hispanomys moralesi sp. nov., is created for it. The samples from the various localities show differences interpreted as being the result of slight age disparities amongst the different sites. Although they were previously thought to be coeval, Batallones 10 is probably older than Batallones 1, which is possibly older than Batallones 3. Hispanomys moralesi sp. nov. is characterized by several morphological features such as the lack of cingula and mesolophs, the presence of well-developed ectolophs, four- or five-rooted M1, short or absent mesolophids, and reduced and simplified M3. Hispanomys moralesi sp. nov. is a relatively derived species, the evolutionary stage of which is comparable to those of other members of the genus from the Upper Vallesian., 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 Ramón 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.

García-Paredes, Israel, Peláez-Campomanes, Pablo, Álvarez-Sierra, M. Ángeles (2009): Gliridae (Rodentia, Mammalia) with a simple dental pattern: a new genus and new species from the European Early and Middle Miocene. Zoological Journal of the Linnean Society 157 (3): 622-652, DOI: 10.1111/j.1096-3642.2009.00527.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2009.00527.x

SIMPLOMYS ROBUSTUS (DE BRUIJN, 1967) (FIG. 5) Original diagnosis (De Bruijn, 1967: 259, translated from Spanish): ‘[Large Pseudodryomys with simple dental pattern. The upper molars have neither centrolophs nor extra ridges. The m1 and m2 have a small centrolophid. The m3 is reduced]’. Emended diagnosis by Daams (1974: 236): ‘ Pseudodryomys -assemblages consisting of large teeth which differ from P. simplicidens in size and in the less reduced m3. The dental patterns of the other molars are identical of those of P. simplicidens ’. Emended diagnosis: Large Simplomys in which the dental pattern in m1 and m2 is formed by the four main ridges and a well-developed centrolophid. The latter extends diagonally into the central valley but never exceeds the middle part of the occlusal surface. The m3 always has a posterior valley and shows little reduction in its posterior part. The M1 may rarely present a small anterior centroloph. Differential diagnosis: Simplomys robustus differs from S. simplicidens by having the premolars and the m3 less reduced in size and less simplified in morphology. The posterior valley of m3 is, in contrast to S. simplicidens, always present. When both species occur in the same assemblage, S. robustus is always larger than S. simplicidens. Type locality: Ateca 3, Calatayud–Montalbán basin, Spain (local zone Z, MN 3, Lower Miocene). Stratigraphical distribution: Local zones Z to C (MN 3–MN 4, Lower Miocene). Geographical distribution: Spain, Portugal, and France., Published as part of García-Paredes, Israel, Peláez-Campomanes, Pablo & Álvarez-Sierra, M. Ángeles, 2009, Gliridae (Rodentia, Mammalia) with a simple dental pattern: a new genus and new species from the European Early and Middle Miocene, pp. 622-652 in Zoological Journal of the Linnean Society 157 (3) on page 640, DOI: 10.1111/j.1096-3642.2009.00527.x, http://zenodo.org/record/5443075, {"references":["De Bruijn H. 1967. Gliridae, Sciuridae y Eomyidae (Rodentia, Mammalia) miocenos de Calatayud (provincia de Zaragoza, Espana) y su relacion con la bioestratigrafia del area. Boletin del Instituto Geologico y Minero de Espana 78: 189 - 373.","Daams R. 1974. Pseudodryomys (Gliridae, Rodentia, Mammalia) from Early and Middle Miocene deposits in Spain. Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen Series B 77: 201 - 240."]}

77 págs, 24 láms., The Cerro de los Batallones (Los Batallones Butte) is located in the central-northern area of the Madrid Basin, central Spain. Nine vertebrates localities containing a large variety of mammals of Upper Vallesian Age (Late Miocene) have been found associated with the sediments forming the butte. From bottom to top, these sediments consist of magnesian lutite beds (Unit I), paleosols formed of sepiolite and opal (Unit II), and siliclastic, marlstone and carbonate beds (Unit III). The set of ERT profiles developed in Los Batallones Butte have demonstrate that electrical imaging techniques are an estimable tool for the characterization and prospecting of fossil sites developed in fine-grained siliciclastic sequences. These localities contain an exceptionally rich, varied and well-preserved vertebrate fauna together with invertebrate and plant fossils. Carnivore species are strikingly well represented at Batallones 1 and 3, and large herbivore species, such as mastodons, rhinoceros and giraffes, at Batallones 2, 4, 5 and 10. The taphonomical studies, together with the morphological features shown by the sedimentary fills of the mammal localities, permit an overall interpretation of these deposits as vertebrate traps. The study of these localities should offer a significant contribution to our understanding of the formation pattern of trap-like paleontological sites - which so far have been typically reported in karstic-type systems -, as well as an important source of paleobiological information about numerous vertebrate groups., Nuestro sincero agradecimiento a la Comunidad de Madrid (Dirección General de Patrimonio Histórico Artístico) por su apoyo a lo largo de todos estos años. A la empresa TOLSA, SA por su inapreciable ayuda en todas las circunstancias. National Geographic Society financió la campaña de Batallones-1 del año 2001. Son muchos los compañeros y amigos que han participado en las excavaciones, y en los diferentes proyectos de investigación de estos yacimientos, a todos ellos nuestro más sincero agradecimiento y nuestros mejores deseos, con la esperanza de seguir contando con su valiosa colaboración. Este trabajo se ha realizado en el marco de los proyectos de investigación MEC 2005-03900/BTE y CGL2006-01773/BTE, y del Grupo de Investigación CAM-UCM 910607.

The micromammal fauna from the Middle Miocene (Middle Aragonian) of La Retama, eastern central Spain, is described. It is a relatively poor rodent fauna composed by ten species only, associated to a highly diverse bat fauna, which includes five genera. The insectivores are represented by two species. This fossil assemblage has been correlated to zone Db (MN 5). The palaeoenvironmental reconstruction based on micromammals indicates open and dry conditions for this locality., Se describen los micromamíferos del Mioceno medio (Aragoniense medio) de La Retama, sector centro-oriental español. La fauna de roedores es relativamente pobre y está compuesta únicamente por diez especies. Sin embargo, cabe destacar la elevada diversidad de los quirópteros, representados por cinco géneros. Se describe también dos taxa de insectívoros. Esta asociación fósil ha sido correlacionada con la zona Db (MN5). La reconstrucción paleoambiental de La Retama inferida a partir de la fauna de micromamíferos corresponde a un ambiente abierto y seco., We acknowledge financial support by the MEC projects D.G.I.C.Y.T. Nº PB92-0013, CGL2004-02094/BTE, MCYT-DGI-SGPDI BTE2002-00410, CGL 2005-03900/BTE, the Research Group CAM-UCM 910607 and the Junta de Comunidades de Castilla-La Mancha.

The paleontological sites of Toril 3A and B (Upper Aragonian, Biozone C3, MN 7/8) posses an exceptional and abundant fauna of vertebrates. From 1997 until 2001 these two localities have been object of systematic paleontological excavations. Up to now 36 species of large and small mammals have been found in these localities; the association of vertebrates also includes amphibians, reptiles and birds, among the remains of fossils birds it is frequent to found egg shell fragments. There are not significant differences in the qualitative and quantitative faunistic composition of the two sites; in both the undetermined bone fragments and the remains of chelonians, most of them dermal bones, are the dominant fossils. An important characteristic is the abundance of small size hornless ruminants, which are quite scarce in the stratified sites of the Spanish Aragonian. Neither there are differences in the composition of the micromammals, the association is overwhelmingly dominated (more than 95%) for different cricetid species; in Toril 3A beavers reappears for the first time during the Aragonian, and they will be frequent in younger faunas of the same basin. The fossils were deposited in different sedimentary environments, related with alluvial and shallow lacustrine environments.

In this paper the micromammals from three localities in the Oligocene/Miocene boundary interval and the Lower Miocene of the Ebro Basin in the Province of Huesca (northern Spain) are described. Twenty-five species are recognized, two of which are new (Quercomys daamsi de Visser and Peridyromys turbatus Alvarez Sierra et al.; Gliridae). One new subspecies belonging to the Ochotonidae (Prolagus vasconiensis fortis López Martínez & Sesé) is described. The biostratigraphy, palaeoecological implications and palaeobiogeography are discussed. Resumen: En este artículo se describen los micromamíferos de tres localidades en el intervalo del límite Oligoceno/Mioceno y el Mioceno inferior de la Cuenca del Ebro, en la provincia de Huesca (norte de España). Se han identificado veinticinco especies, dos de las cuales son nuevas (Quercomys daamsi de Visser y Peridyromys turbatus Alvarez Sierra et al;. Gliridae). Se describe una nueva subespecie perteneciente a los Ochotonidae (Prolagus vasconiensis fortis López Martínez y Sesé). Se discute la bioestratigrafía, implicaciones paleoecológicas y paleobiogeografía.

Tesis doctoral inédita. Universidad Autónoma de Madrid, [Facultad de Ciencias, Departamento de Biología]. Fecha de lectura: 08-11-2013